The value of tan20 tan25 tan45 tan65 tan70 is ………….

If cos²45 – cos²30 = x ⋅ cos45 ⋅ sin45, then x is …….

If A and B are complementary angles, then sinA ⋅ secB is ____

If 7θ and 2θ are measure of acute angles such that sin7θ = cos2θ then 2sin3θ — √3 tan3θ is ……….

If A + B = 90, then is ….