?² × 25 = 4² × 21 + 17² 

If 2y . cos θ - x . sin θ = 0 and 2x . sec θ - y . cosec θ = 3, what is the value of x² + 4y²?

If P, Q, R, S are the vertex of a cyclic quadrilateral. Find the value of

`1/sec p` +`1/sec q` +`1/sec r` +`1/sec s`

If cot A = 12/5, then the value of (sin A + cos A) × sec A is ________.

If θ is an acute angle and sin θ + cosec θ = 2, then the value of sin² θ + cosec² θ is:

If 4sin² θ = 3(1+ cos θ), 0° < θ < 90°, then what is the value of (2tan θ + 4sinθ - secθ)?

If tan θ = 8/3 , then the value of (3Sinθ+2 Cosθ )/(3 Sinθ-2Cosθ) is