If tan⁴θ + tan²θ = 1, then the value of cos⁴θ + cos²θ is

If sinθ – cosθ = 7/13 and 0⁰ < θ < 90⁰ , then the value of sinθ + cosθ is :

If sinθ + cosecθ = 2, then the value of $$ sin^9 θ +cosec^9θ $$ is –

A tower standing on a horizontal plane subtends a certain angle at a point 160 m apart from the foot of the tower. On advancing 100 m towards it, the tower is found to subtend and angle twice as before. The height of the tower is

The value of $$ sec{^4}A(1-sin{^4}A)-2tan{^2}A $$ is:

If tan $$ -{7π\over4}=x $$ then the value of x is :