CUET Preparation Today
If cosθ + sec θ = 10 , find the value of cos2θ + sec2θ . |
95 98 102 100 |
98 |
Formula I → [ cosθ = \(\frac{1}{secθ}\)] Formula II → [If x + \(\frac{1}{x}\) = n and x2 + \(\frac{1}{x^2}\) = n2 - 2] cosθ + \(\frac{1}{cosθ}\) = 10 ⇒ cos2θ + \(\frac{1}{cos^2θ}\) = (10)2 - 2 ⇒ cos2θ + sec2θ = 100 - 2 = 98 |
