If 2x = sin θ and $\frac{2}{x}=cosθ$ then the value of $4(x^2+\frac{1}{x^2})$ is :
Answer & explanation
Correct answer: option 4
Given :-
2x = sin θ & \(\frac{2 }{x}\) = cosθ
Squaring both sides
4x² = sin²θ -----(1)
\(\frac{4 }{x²}\) = cos²θ ----(2)
Adding equation 1 and 2.
sin²θ + cos²θ = 4x² + \(\frac{4 }{x²}\)
{ sin²θ + cos²θ = 1 }
1 = 4x² + \(\frac{4 }{x²}\)
Ans :- 1