m2m模型翻译
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  1. from sympy.core.function import (Subs, count_ops, diff, expand)
  2. from sympy.core.numbers import (E, I, Rational, pi)
  3. from sympy.core.singleton import S
  4. from sympy.core.symbol import (Symbol, symbols)
  5. from sympy.functions.elementary.exponential import (exp, log)
  6. from sympy.functions.elementary.hyperbolic import (cosh, coth, sinh, tanh)
  7. from sympy.functions.elementary.miscellaneous import sqrt
  8. from sympy.functions.elementary.piecewise import Piecewise
  9. from sympy.functions.elementary.trigonometric import (cos, cot, sin, tan)
  10. from sympy.integrals.integrals import integrate
  11. from sympy.matrices.dense import Matrix
  12. from sympy.simplify.simplify import simplify
  13. from sympy.simplify.trigsimp import (exptrigsimp, trigsimp)
  14. from sympy.testing.pytest import XFAIL
  15. from sympy.abc import x, y
  16. def test_trigsimp1():
  17. x, y = symbols('x,y')
  18. assert trigsimp(1 - sin(x)**2) == cos(x)**2
  19. assert trigsimp(1 - cos(x)**2) == sin(x)**2
  20. assert trigsimp(sin(x)**2 + cos(x)**2) == 1
  21. assert trigsimp(1 + tan(x)**2) == 1/cos(x)**2
  22. assert trigsimp(1/cos(x)**2 - 1) == tan(x)**2
  23. assert trigsimp(1/cos(x)**2 - tan(x)**2) == 1
  24. assert trigsimp(1 + cot(x)**2) == 1/sin(x)**2
  25. assert trigsimp(1/sin(x)**2 - 1) == 1/tan(x)**2
  26. assert trigsimp(1/sin(x)**2 - cot(x)**2) == 1
  27. assert trigsimp(5*cos(x)**2 + 5*sin(x)**2) == 5
  28. assert trigsimp(5*cos(x/2)**2 + 2*sin(x/2)**2) == 3*cos(x)/2 + Rational(7, 2)
  29. assert trigsimp(sin(x)/cos(x)) == tan(x)
  30. assert trigsimp(2*tan(x)*cos(x)) == 2*sin(x)
  31. assert trigsimp(cot(x)**3*sin(x)**3) == cos(x)**3
  32. assert trigsimp(y*tan(x)**2/sin(x)**2) == y/cos(x)**2
  33. assert trigsimp(cot(x)/cos(x)) == 1/sin(x)
  34. assert trigsimp(sin(x + y) + sin(x - y)) == 2*sin(x)*cos(y)
  35. assert trigsimp(sin(x + y) - sin(x - y)) == 2*sin(y)*cos(x)
  36. assert trigsimp(cos(x + y) + cos(x - y)) == 2*cos(x)*cos(y)
  37. assert trigsimp(cos(x + y) - cos(x - y)) == -2*sin(x)*sin(y)
  38. assert trigsimp(tan(x + y) - tan(x)/(1 - tan(x)*tan(y))) == \
  39. sin(y)/(-sin(y)*tan(x) + cos(y)) # -tan(y)/(tan(x)*tan(y) - 1)
  40. assert trigsimp(sinh(x + y) + sinh(x - y)) == 2*sinh(x)*cosh(y)
  41. assert trigsimp(sinh(x + y) - sinh(x - y)) == 2*sinh(y)*cosh(x)
  42. assert trigsimp(cosh(x + y) + cosh(x - y)) == 2*cosh(x)*cosh(y)
  43. assert trigsimp(cosh(x + y) - cosh(x - y)) == 2*sinh(x)*sinh(y)
  44. assert trigsimp(tanh(x + y) - tanh(x)/(1 + tanh(x)*tanh(y))) == \
  45. sinh(y)/(sinh(y)*tanh(x) + cosh(y))
  46. assert trigsimp(cos(0.12345)**2 + sin(0.12345)**2) == 1
  47. e = 2*sin(x)**2 + 2*cos(x)**2
  48. assert trigsimp(log(e)) == log(2)
  49. def test_trigsimp1a():
  50. assert trigsimp(sin(2)**2*cos(3)*exp(2)/cos(2)**2) == tan(2)**2*cos(3)*exp(2)
  51. assert trigsimp(tan(2)**2*cos(3)*exp(2)*cos(2)**2) == sin(2)**2*cos(3)*exp(2)
  52. assert trigsimp(cot(2)*cos(3)*exp(2)*sin(2)) == cos(3)*exp(2)*cos(2)
  53. assert trigsimp(tan(2)*cos(3)*exp(2)/sin(2)) == cos(3)*exp(2)/cos(2)
  54. assert trigsimp(cot(2)*cos(3)*exp(2)/cos(2)) == cos(3)*exp(2)/sin(2)
  55. assert trigsimp(cot(2)*cos(3)*exp(2)*tan(2)) == cos(3)*exp(2)
  56. assert trigsimp(sinh(2)*cos(3)*exp(2)/cosh(2)) == tanh(2)*cos(3)*exp(2)
  57. assert trigsimp(tanh(2)*cos(3)*exp(2)*cosh(2)) == sinh(2)*cos(3)*exp(2)
  58. assert trigsimp(coth(2)*cos(3)*exp(2)*sinh(2)) == cosh(2)*cos(3)*exp(2)
  59. assert trigsimp(tanh(2)*cos(3)*exp(2)/sinh(2)) == cos(3)*exp(2)/cosh(2)
  60. assert trigsimp(coth(2)*cos(3)*exp(2)/cosh(2)) == cos(3)*exp(2)/sinh(2)
  61. assert trigsimp(coth(2)*cos(3)*exp(2)*tanh(2)) == cos(3)*exp(2)
  62. def test_trigsimp2():
  63. x, y = symbols('x,y')
  64. assert trigsimp(cos(x)**2*sin(y)**2 + cos(x)**2*cos(y)**2 + sin(x)**2,
  65. recursive=True) == 1
  66. assert trigsimp(sin(x)**2*sin(y)**2 + sin(x)**2*cos(y)**2 + cos(x)**2,
  67. recursive=True) == 1
  68. assert trigsimp(
  69. Subs(x, x, sin(y)**2 + cos(y)**2)) == Subs(x, x, 1)
  70. def test_issue_4373():
  71. x = Symbol("x")
  72. assert abs(trigsimp(2.0*sin(x)**2 + 2.0*cos(x)**2) - 2.0) < 1e-10
  73. def test_trigsimp3():
  74. x, y = symbols('x,y')
  75. assert trigsimp(sin(x)/cos(x)) == tan(x)
  76. assert trigsimp(sin(x)**2/cos(x)**2) == tan(x)**2
  77. assert trigsimp(sin(x)**3/cos(x)**3) == tan(x)**3
  78. assert trigsimp(sin(x)**10/cos(x)**10) == tan(x)**10
  79. assert trigsimp(cos(x)/sin(x)) == 1/tan(x)
  80. assert trigsimp(cos(x)**2/sin(x)**2) == 1/tan(x)**2
  81. assert trigsimp(cos(x)**10/sin(x)**10) == 1/tan(x)**10
  82. assert trigsimp(tan(x)) == trigsimp(sin(x)/cos(x))
  83. def test_issue_4661():
  84. a, x, y = symbols('a x y')
  85. eq = -4*sin(x)**4 + 4*cos(x)**4 - 8*cos(x)**2
  86. assert trigsimp(eq) == -4
  87. n = sin(x)**6 + 4*sin(x)**4*cos(x)**2 + 5*sin(x)**2*cos(x)**4 + 2*cos(x)**6
  88. d = -sin(x)**2 - 2*cos(x)**2
  89. assert simplify(n/d) == -1
  90. assert trigsimp(-2*cos(x)**2 + cos(x)**4 - sin(x)**4) == -1
  91. eq = (- sin(x)**3/4)*cos(x) + (cos(x)**3/4)*sin(x) - sin(2*x)*cos(2*x)/8
  92. assert trigsimp(eq) == 0
  93. def test_issue_4494():
  94. a, b = symbols('a b')
  95. eq = sin(a)**2*sin(b)**2 + cos(a)**2*cos(b)**2*tan(a)**2 + cos(a)**2
  96. assert trigsimp(eq) == 1
  97. def test_issue_5948():
  98. a, x, y = symbols('a x y')
  99. assert trigsimp(diff(integrate(cos(x)/sin(x)**7, x), x)) == \
  100. cos(x)/sin(x)**7
  101. def test_issue_4775():
  102. a, x, y = symbols('a x y')
  103. assert trigsimp(sin(x)*cos(y)+cos(x)*sin(y)) == sin(x + y)
  104. assert trigsimp(sin(x)*cos(y)+cos(x)*sin(y)+3) == sin(x + y) + 3
  105. def test_issue_4280():
  106. a, x, y = symbols('a x y')
  107. assert trigsimp(cos(x)**2 + cos(y)**2*sin(x)**2 + sin(y)**2*sin(x)**2) == 1
  108. assert trigsimp(a**2*sin(x)**2 + a**2*cos(y)**2*cos(x)**2 + a**2*cos(x)**2*sin(y)**2) == a**2
  109. assert trigsimp(a**2*cos(y)**2*sin(x)**2 + a**2*sin(y)**2*sin(x)**2) == a**2*sin(x)**2
  110. def test_issue_3210():
  111. eqs = (sin(2)*cos(3) + sin(3)*cos(2),
  112. -sin(2)*sin(3) + cos(2)*cos(3),
  113. sin(2)*cos(3) - sin(3)*cos(2),
  114. sin(2)*sin(3) + cos(2)*cos(3),
  115. sin(2)*sin(3) + cos(2)*cos(3) + cos(2),
  116. sinh(2)*cosh(3) + sinh(3)*cosh(2),
  117. sinh(2)*sinh(3) + cosh(2)*cosh(3),
  118. )
  119. assert [trigsimp(e) for e in eqs] == [
  120. sin(5),
  121. cos(5),
  122. -sin(1),
  123. cos(1),
  124. cos(1) + cos(2),
  125. sinh(5),
  126. cosh(5),
  127. ]
  128. def test_trigsimp_issues():
  129. a, x, y = symbols('a x y')
  130. # issue 4625 - factor_terms works, too
  131. assert trigsimp(sin(x)**3 + cos(x)**2*sin(x)) == sin(x)
  132. # issue 5948
  133. assert trigsimp(diff(integrate(cos(x)/sin(x)**3, x), x)) == \
  134. cos(x)/sin(x)**3
  135. assert trigsimp(diff(integrate(sin(x)/cos(x)**3, x), x)) == \
  136. sin(x)/cos(x)**3
  137. # check integer exponents
  138. e = sin(x)**y/cos(x)**y
  139. assert trigsimp(e) == e
  140. assert trigsimp(e.subs(y, 2)) == tan(x)**2
  141. assert trigsimp(e.subs(x, 1)) == tan(1)**y
  142. # check for multiple patterns
  143. assert (cos(x)**2/sin(x)**2*cos(y)**2/sin(y)**2).trigsimp() == \
  144. 1/tan(x)**2/tan(y)**2
  145. assert trigsimp(cos(x)/sin(x)*cos(x+y)/sin(x+y)) == \
  146. 1/(tan(x)*tan(x + y))
  147. eq = cos(2)*(cos(3) + 1)**2/(cos(3) - 1)**2
  148. assert trigsimp(eq) == eq.factor() # factor makes denom (-1 + cos(3))**2
  149. assert trigsimp(cos(2)*(cos(3) + 1)**2*(cos(3) - 1)**2) == \
  150. cos(2)*sin(3)**4
  151. # issue 6789; this generates an expression that formerly caused
  152. # trigsimp to hang
  153. assert cot(x).equals(tan(x)) is False
  154. # nan or the unchanged expression is ok, but not sin(1)
  155. z = cos(x)**2 + sin(x)**2 - 1
  156. z1 = tan(x)**2 - 1/cot(x)**2
  157. n = (1 + z1/z)
  158. assert trigsimp(sin(n)) != sin(1)
  159. eq = x*(n - 1) - x*n
  160. assert trigsimp(eq) is S.NaN
  161. assert trigsimp(eq, recursive=True) is S.NaN
  162. assert trigsimp(1).is_Integer
  163. assert trigsimp(-sin(x)**4 - 2*sin(x)**2*cos(x)**2 - cos(x)**4) == -1
  164. def test_trigsimp_issue_2515():
  165. x = Symbol('x')
  166. assert trigsimp(x*cos(x)*tan(x)) == x*sin(x)
  167. assert trigsimp(-sin(x) + cos(x)*tan(x)) == 0
  168. def test_trigsimp_issue_3826():
  169. assert trigsimp(tan(2*x).expand(trig=True)) == tan(2*x)
  170. def test_trigsimp_issue_4032():
  171. n = Symbol('n', integer=True, positive=True)
  172. assert trigsimp(2**(n/2)*cos(pi*n/4)/2 + 2**(n - 1)/2) == \
  173. 2**(n/2)*cos(pi*n/4)/2 + 2**n/4
  174. def test_trigsimp_issue_7761():
  175. assert trigsimp(cosh(pi/4)) == cosh(pi/4)
  176. def test_trigsimp_noncommutative():
  177. x, y = symbols('x,y')
  178. A, B = symbols('A,B', commutative=False)
  179. assert trigsimp(A - A*sin(x)**2) == A*cos(x)**2
  180. assert trigsimp(A - A*cos(x)**2) == A*sin(x)**2
  181. assert trigsimp(A*sin(x)**2 + A*cos(x)**2) == A
  182. assert trigsimp(A + A*tan(x)**2) == A/cos(x)**2
  183. assert trigsimp(A/cos(x)**2 - A) == A*tan(x)**2
  184. assert trigsimp(A/cos(x)**2 - A*tan(x)**2) == A
  185. assert trigsimp(A + A*cot(x)**2) == A/sin(x)**2
  186. assert trigsimp(A/sin(x)**2 - A) == A/tan(x)**2
  187. assert trigsimp(A/sin(x)**2 - A*cot(x)**2) == A
  188. assert trigsimp(y*A*cos(x)**2 + y*A*sin(x)**2) == y*A
  189. assert trigsimp(A*sin(x)/cos(x)) == A*tan(x)
  190. assert trigsimp(A*tan(x)*cos(x)) == A*sin(x)
  191. assert trigsimp(A*cot(x)**3*sin(x)**3) == A*cos(x)**3
  192. assert trigsimp(y*A*tan(x)**2/sin(x)**2) == y*A/cos(x)**2
  193. assert trigsimp(A*cot(x)/cos(x)) == A/sin(x)
  194. assert trigsimp(A*sin(x + y) + A*sin(x - y)) == 2*A*sin(x)*cos(y)
  195. assert trigsimp(A*sin(x + y) - A*sin(x - y)) == 2*A*sin(y)*cos(x)
  196. assert trigsimp(A*cos(x + y) + A*cos(x - y)) == 2*A*cos(x)*cos(y)
  197. assert trigsimp(A*cos(x + y) - A*cos(x - y)) == -2*A*sin(x)*sin(y)
  198. assert trigsimp(A*sinh(x + y) + A*sinh(x - y)) == 2*A*sinh(x)*cosh(y)
  199. assert trigsimp(A*sinh(x + y) - A*sinh(x - y)) == 2*A*sinh(y)*cosh(x)
  200. assert trigsimp(A*cosh(x + y) + A*cosh(x - y)) == 2*A*cosh(x)*cosh(y)
  201. assert trigsimp(A*cosh(x + y) - A*cosh(x - y)) == 2*A*sinh(x)*sinh(y)
  202. assert trigsimp(A*cos(0.12345)**2 + A*sin(0.12345)**2) == 1.0*A
  203. def test_hyperbolic_simp():
  204. x, y = symbols('x,y')
  205. assert trigsimp(sinh(x)**2 + 1) == cosh(x)**2
  206. assert trigsimp(cosh(x)**2 - 1) == sinh(x)**2
  207. assert trigsimp(cosh(x)**2 - sinh(x)**2) == 1
  208. assert trigsimp(1 - tanh(x)**2) == 1/cosh(x)**2
  209. assert trigsimp(1 - 1/cosh(x)**2) == tanh(x)**2
  210. assert trigsimp(tanh(x)**2 + 1/cosh(x)**2) == 1
  211. assert trigsimp(coth(x)**2 - 1) == 1/sinh(x)**2
  212. assert trigsimp(1/sinh(x)**2 + 1) == 1/tanh(x)**2
  213. assert trigsimp(coth(x)**2 - 1/sinh(x)**2) == 1
  214. assert trigsimp(5*cosh(x)**2 - 5*sinh(x)**2) == 5
  215. assert trigsimp(5*cosh(x/2)**2 - 2*sinh(x/2)**2) == 3*cosh(x)/2 + Rational(7, 2)
  216. assert trigsimp(sinh(x)/cosh(x)) == tanh(x)
  217. assert trigsimp(tanh(x)) == trigsimp(sinh(x)/cosh(x))
  218. assert trigsimp(cosh(x)/sinh(x)) == 1/tanh(x)
  219. assert trigsimp(2*tanh(x)*cosh(x)) == 2*sinh(x)
  220. assert trigsimp(coth(x)**3*sinh(x)**3) == cosh(x)**3
  221. assert trigsimp(y*tanh(x)**2/sinh(x)**2) == y/cosh(x)**2
  222. assert trigsimp(coth(x)/cosh(x)) == 1/sinh(x)
  223. for a in (pi/6*I, pi/4*I, pi/3*I):
  224. assert trigsimp(sinh(a)*cosh(x) + cosh(a)*sinh(x)) == sinh(x + a)
  225. assert trigsimp(-sinh(a)*cosh(x) + cosh(a)*sinh(x)) == sinh(x - a)
  226. e = 2*cosh(x)**2 - 2*sinh(x)**2
  227. assert trigsimp(log(e)) == log(2)
  228. # issue 19535:
  229. assert trigsimp(sqrt(cosh(x)**2 - 1)) == sqrt(sinh(x)**2)
  230. assert trigsimp(cosh(x)**2*cosh(y)**2 - cosh(x)**2*sinh(y)**2 - sinh(x)**2,
  231. recursive=True) == 1
  232. assert trigsimp(sinh(x)**2*sinh(y)**2 - sinh(x)**2*cosh(y)**2 + cosh(x)**2,
  233. recursive=True) == 1
  234. assert abs(trigsimp(2.0*cosh(x)**2 - 2.0*sinh(x)**2) - 2.0) < 1e-10
  235. assert trigsimp(sinh(x)**2/cosh(x)**2) == tanh(x)**2
  236. assert trigsimp(sinh(x)**3/cosh(x)**3) == tanh(x)**3
  237. assert trigsimp(sinh(x)**10/cosh(x)**10) == tanh(x)**10
  238. assert trigsimp(cosh(x)**3/sinh(x)**3) == 1/tanh(x)**3
  239. assert trigsimp(cosh(x)/sinh(x)) == 1/tanh(x)
  240. assert trigsimp(cosh(x)**2/sinh(x)**2) == 1/tanh(x)**2
  241. assert trigsimp(cosh(x)**10/sinh(x)**10) == 1/tanh(x)**10
  242. assert trigsimp(x*cosh(x)*tanh(x)) == x*sinh(x)
  243. assert trigsimp(-sinh(x) + cosh(x)*tanh(x)) == 0
  244. assert tan(x) != 1/cot(x) # cot doesn't auto-simplify
  245. assert trigsimp(tan(x) - 1/cot(x)) == 0
  246. assert trigsimp(3*tanh(x)**7 - 2/coth(x)**7) == tanh(x)**7
  247. def test_trigsimp_groebner():
  248. from sympy.simplify.trigsimp import trigsimp_groebner
  249. c = cos(x)
  250. s = sin(x)
  251. ex = (4*s*c + 12*s + 5*c**3 + 21*c**2 + 23*c + 15)/(
  252. -s*c**2 + 2*s*c + 15*s + 7*c**3 + 31*c**2 + 37*c + 21)
  253. resnum = (5*s - 5*c + 1)
  254. resdenom = (8*s - 6*c)
  255. results = [resnum/resdenom, (-resnum)/(-resdenom)]
  256. assert trigsimp_groebner(ex) in results
  257. assert trigsimp_groebner(s/c, hints=[tan]) == tan(x)
  258. assert trigsimp_groebner(c*s) == c*s
  259. assert trigsimp((-s + 1)/c + c/(-s + 1),
  260. method='groebner') == 2/c
  261. assert trigsimp((-s + 1)/c + c/(-s + 1),
  262. method='groebner', polynomial=True) == 2/c
  263. # Test quick=False works
  264. assert trigsimp_groebner(ex, hints=[2]) in results
  265. assert trigsimp_groebner(ex, hints=[int(2)]) in results
  266. # test "I"
  267. assert trigsimp_groebner(sin(I*x)/cos(I*x), hints=[tanh]) == I*tanh(x)
  268. # test hyperbolic / sums
  269. assert trigsimp_groebner((tanh(x)+tanh(y))/(1+tanh(x)*tanh(y)),
  270. hints=[(tanh, x, y)]) == tanh(x + y)
  271. def test_issue_2827_trigsimp_methods():
  272. measure1 = lambda expr: len(str(expr))
  273. measure2 = lambda expr: -count_ops(expr)
  274. # Return the most complicated result
  275. expr = (x + 1)/(x + sin(x)**2 + cos(x)**2)
  276. ans = Matrix([1])
  277. M = Matrix([expr])
  278. assert trigsimp(M, method='fu', measure=measure1) == ans
  279. assert trigsimp(M, method='fu', measure=measure2) != ans
  280. # all methods should work with Basic expressions even if they
  281. # aren't Expr
  282. M = Matrix.eye(1)
  283. assert all(trigsimp(M, method=m) == M for m in
  284. 'fu matching groebner old'.split())
  285. # watch for E in exptrigsimp, not only exp()
  286. eq = 1/sqrt(E) + E
  287. assert exptrigsimp(eq) == eq
  288. def test_issue_15129_trigsimp_methods():
  289. t1 = Matrix([sin(Rational(1, 50)), cos(Rational(1, 50)), 0])
  290. t2 = Matrix([sin(Rational(1, 25)), cos(Rational(1, 25)), 0])
  291. t3 = Matrix([cos(Rational(1, 25)), sin(Rational(1, 25)), 0])
  292. r1 = t1.dot(t2)
  293. r2 = t1.dot(t3)
  294. assert trigsimp(r1) == cos(Rational(1, 50))
  295. assert trigsimp(r2) == sin(Rational(3, 50))
  296. def test_exptrigsimp():
  297. def valid(a, b):
  298. from sympy.core.random import verify_numerically as tn
  299. if not (tn(a, b) and a == b):
  300. return False
  301. return True
  302. assert exptrigsimp(exp(x) + exp(-x)) == 2*cosh(x)
  303. assert exptrigsimp(exp(x) - exp(-x)) == 2*sinh(x)
  304. assert exptrigsimp((2*exp(x)-2*exp(-x))/(exp(x)+exp(-x))) == 2*tanh(x)
  305. assert exptrigsimp((2*exp(2*x)-2)/(exp(2*x)+1)) == 2*tanh(x)
  306. e = [cos(x) + I*sin(x), cos(x) - I*sin(x),
  307. cosh(x) - sinh(x), cosh(x) + sinh(x)]
  308. ok = [exp(I*x), exp(-I*x), exp(-x), exp(x)]
  309. assert all(valid(i, j) for i, j in zip(
  310. [exptrigsimp(ei) for ei in e], ok))
  311. ue = [cos(x) + sin(x), cos(x) - sin(x),
  312. cosh(x) + I*sinh(x), cosh(x) - I*sinh(x)]
  313. assert [exptrigsimp(ei) == ei for ei in ue]
  314. res = []
  315. ok = [y*tanh(1), 1/(y*tanh(1)), I*y*tan(1), -I/(y*tan(1)),
  316. y*tanh(x), 1/(y*tanh(x)), I*y*tan(x), -I/(y*tan(x)),
  317. y*tanh(1 + I), 1/(y*tanh(1 + I))]
  318. for a in (1, I, x, I*x, 1 + I):
  319. w = exp(a)
  320. eq = y*(w - 1/w)/(w + 1/w)
  321. res.append(simplify(eq))
  322. res.append(simplify(1/eq))
  323. assert all(valid(i, j) for i, j in zip(res, ok))
  324. for a in range(1, 3):
  325. w = exp(a)
  326. e = w + 1/w
  327. s = simplify(e)
  328. assert s == exptrigsimp(e)
  329. assert valid(s, 2*cosh(a))
  330. e = w - 1/w
  331. s = simplify(e)
  332. assert s == exptrigsimp(e)
  333. assert valid(s, 2*sinh(a))
  334. def test_exptrigsimp_noncommutative():
  335. a,b = symbols('a b', commutative=False)
  336. x = Symbol('x', commutative=True)
  337. assert exp(a + x) == exptrigsimp(exp(a)*exp(x))
  338. p = exp(a)*exp(b) - exp(b)*exp(a)
  339. assert p == exptrigsimp(p) != 0
  340. def test_powsimp_on_numbers():
  341. assert 2**(Rational(1, 3) - 2) == 2**Rational(1, 3)/4
  342. @XFAIL
  343. def test_issue_6811_fail():
  344. # from doc/src/modules/physics/mechanics/examples.rst, the current `eq`
  345. # at Line 576 (in different variables) was formerly the equivalent and
  346. # shorter expression given below...it would be nice to get the short one
  347. # back again
  348. xp, y, x, z = symbols('xp, y, x, z')
  349. eq = 4*(-19*sin(x)*y + 5*sin(3*x)*y + 15*cos(2*x)*z - 21*z)*xp/(9*cos(x) - 5*cos(3*x))
  350. assert trigsimp(eq) == -2*(2*cos(x)*tan(x)*y + 3*z)*xp/cos(x)
  351. def test_Piecewise():
  352. e1 = x*(x + y) - y*(x + y)
  353. e2 = sin(x)**2 + cos(x)**2
  354. e3 = expand((x + y)*y/x)
  355. # s1 = simplify(e1)
  356. s2 = simplify(e2)
  357. # s3 = simplify(e3)
  358. # trigsimp tries not to touch non-trig containing args
  359. assert trigsimp(Piecewise((e1, e3 < e2), (e3, True))) == \
  360. Piecewise((e1, e3 < s2), (e3, True))
  361. def test_issue_21594():
  362. assert simplify(exp(Rational(1,2)) + exp(Rational(-1,2))) == cosh(S.Half)*2
  363. def test_trigsimp_old():
  364. x, y = symbols('x,y')
  365. assert trigsimp(1 - sin(x)**2, old=True) == cos(x)**2
  366. assert trigsimp(1 - cos(x)**2, old=True) == sin(x)**2
  367. assert trigsimp(sin(x)**2 + cos(x)**2, old=True) == 1
  368. assert trigsimp(1 + tan(x)**2, old=True) == 1/cos(x)**2
  369. assert trigsimp(1/cos(x)**2 - 1, old=True) == tan(x)**2
  370. assert trigsimp(1/cos(x)**2 - tan(x)**2, old=True) == 1
  371. assert trigsimp(1 + cot(x)**2, old=True) == 1/sin(x)**2
  372. assert trigsimp(1/sin(x)**2 - cot(x)**2, old=True) == 1
  373. assert trigsimp(5*cos(x)**2 + 5*sin(x)**2, old=True) == 5
  374. assert trigsimp(sin(x)/cos(x), old=True) == tan(x)
  375. assert trigsimp(2*tan(x)*cos(x), old=True) == 2*sin(x)
  376. assert trigsimp(cot(x)**3*sin(x)**3, old=True) == cos(x)**3
  377. assert trigsimp(y*tan(x)**2/sin(x)**2, old=True) == y/cos(x)**2
  378. assert trigsimp(cot(x)/cos(x), old=True) == 1/sin(x)
  379. assert trigsimp(sin(x + y) + sin(x - y), old=True) == 2*sin(x)*cos(y)
  380. assert trigsimp(sin(x + y) - sin(x - y), old=True) == 2*sin(y)*cos(x)
  381. assert trigsimp(cos(x + y) + cos(x - y), old=True) == 2*cos(x)*cos(y)
  382. assert trigsimp(cos(x + y) - cos(x - y), old=True) == -2*sin(x)*sin(y)
  383. assert trigsimp(sinh(x + y) + sinh(x - y), old=True) == 2*sinh(x)*cosh(y)
  384. assert trigsimp(sinh(x + y) - sinh(x - y), old=True) == 2*sinh(y)*cosh(x)
  385. assert trigsimp(cosh(x + y) + cosh(x - y), old=True) == 2*cosh(x)*cosh(y)
  386. assert trigsimp(cosh(x + y) - cosh(x - y), old=True) == 2*sinh(x)*sinh(y)
  387. assert trigsimp(cos(0.12345)**2 + sin(0.12345)**2, old=True) == 1
  388. assert trigsimp(sin(x)/cos(x), old=True, method='combined') == tan(x)
  389. assert trigsimp(sin(x)/cos(x), old=True, method='groebner') == sin(x)/cos(x)
  390. assert trigsimp(sin(x)/cos(x), old=True, method='groebner', hints=[tan]) == tan(x)
  391. assert trigsimp(1-sin(sin(x)**2+cos(x)**2)**2, old=True, deep=True) == cos(1)**2