CUET Preparation Today
If cosθ - sec θ = 3 , find the value of cos2θ + sec2θ . |
13 9 11 15 |
11 |
Formula I → [ cosθ = \(\frac{1}{secθ}\)] Formula II → [If x - \(\frac{1}{x}\) = n and x2 + \(\frac{1}{x^2}\) = n2 + 2] cosθ - \(\frac{1}{cosθ}\) = 3 ⇒ cos2θ + \(\frac{1}{cos^2θ}\) = (3)2 + 2 ⇒ cos2θ + sec2θ = 9 + 2 = 11 |
