If cosθ - sec θ = 8 , find the value of cos3θ - sec3θ . |
544 520 536 512 |
536 |
Formula I → [ sec = \(\frac{1}{cosθ}\)] Formula II → [If x - \(\frac{1}{x}\) = n and x3 - \(\frac{1}{x^3}\) = n3 + 3n] cosθ - \(\frac{1}{cosθ}\) = 8 ⇒ cos3θ - \(\frac{1}{cos^3θ}\) = (8)3 + 3 × 8 ⇒ cos3θ - sec3θ = 512 + 24 = 536 |