Question

Answer quickly.. If - tan2A =cot(A-18)then find the value of A

Answer 1

Answer:

A = 36 degrees

Step-by-step explanation:

The following identity will be used to solve the above question--

$cot\alpha= tan(90-\alpha)$

Therefore--

$tan2A = cot(A-18)\\tan2A = tan[90-(A-18)]\\tan2A = tan(108-A)\\2A = 108-A\\A = 36$