If secθ + cosθ = 9, find the value of cos3θ + sec3θ.

707 756 702 710

702

Formula → [secθ = \(\frac{1}{cosθ}\) and cosθ = \(\frac{1}{secθ}\)] ⇒ cosθ + \(\frac{1}{cosθ}\) = 9 ⇒ cos3θ + \(\frac{1}{cos^3θ}\) = (9)3 - 9 × 3 ⇒ cos3θ + sec3θ = 729 - 27 = 702