If x + 1 x = 2 cos θ, then x 3 + 1 x ^ 3 =
Mathematics · JEE Main · NTA Exams — Trigonometry
If x + \(\frac{1}{x}\) = 2 cos θ, then x3 + \(\frac{1}{\mathrm{x}^{3}}\) =
- cos 3θ
- 2 cos 3θ
- \(\frac{1}{2}\)cos 3θ
- \(\frac{1}{3}\)cos 3θ
Answer
(B) 2 cos 3 θ
Sign up free on Edukali to view the step-by-step worked solution and practice thousands of similar questions.
Related practice questions
- The value of ^ -1 [ 1+x^ 2 + 1-x^ 2 1+x^ 2 - 1-x^ 2 ], |x|< 1 2 , x 0, is equal to
- ^ -1 ( 1+ 3 3+ 3 )+ ^ -1 ( 8+4 3 6+3 3 ) is equal to
- In a ∆ PQR, if 3 sin P + 4 cos Q = 6 and 4 sin Q + 3 cos P=1, then the angle R is equal to
- If ^ -1 x= cosec ^ -1 y , then ^ -1 ( 1 x )+ ^ -1 ( 1 y ) is equal to:
- The triangle PQR of which the angles P, Q, R satisfy P = Q 2 R , is
- Let 0 2 and x = X cos θ + Y sin θ, y = X sin θ – Y cos θ such that x 2 + 4xy + y 2 = aX 2 + bY 2 , where a, b…
- The sum of the radii of inscribed and circumscribed circles for an n sided regular polygon of side a, is
- Let e^ 105 x -e^ -105 x =4 , then the value of the cos x is