Hello, I would be happy if someone showed me how to solve this question a) By using the substitution t= tan 1/2 x prove that cosec x - cot x = tan 1/2 x b) Use this result to show that tan 15 degrees = 2 - sqrt(3) Thanks in advance.

Follow Math Help Forum on Facebook and Google+

Hello Oasis1993 Originally Posted by Oasis1993 Hello, I would be happy if someone showed me how to solve this question a) By using the substitution t= tan 1/2 x prove that cosec x - cot x = tan 1/2 x b) Use this result to show that tan 15 degrees = 2 - sqrt(3) Thanks in advance. The following formulae are standard results when : So for (a): I'm sure you can finish this now. (b) We know from a triangle, that . So, if : , using the quadratic formula, and taking the positive result since Grandad

View Tag Cloud