Evaluate the following.

sin 25° sin 65° – cos 25° cos 65°.

If sin A=, then what is the value of sec A?

θθθθθ

If 2sinθ+cosθ= then the value of (tan²θ-sec²θ) is

The numerical value of θθ will be 

if (1+sinα) (1-sinβ) (1+sinγ)= (1-sinα) (1-sinβ) (1-sinγ)=?

If θθθ where θ then the value of θ is:

if 2sinθ + 2sin²θ = 2, then the value of 2 cos⁴θ + 2cos²θ is: