Question

cot2theta=tan4theta find sin3theta

Answer 1

put theta is equal to 15 degree then sin three theta is equal to
$1 \div \sqrt{2}$

Answer 2

Tan 90-2A is equal to Tan4A                         90-2A is equal to 4A.                                   A is equal to 15 degrees.                               Sin3A is sin3 into 15 degrees                     That is sin45.                                                 That is 1/route2