How to prove the following identities cos(30°)-cos(60°)\cos(30°)+sin(60°)=tan(15°)?

1 Answer
Aug 12, 2018

A Proof is given in The Explanation.

Explanation:

The Correct Problem is to prove that,

cos30cos60cos30+cos60=tan15.

The Expression=cos30cos60cos30+cos60,

=2sin(30+602)sin(30602)2cos(30+602)cos(30602),

=2sin45sin(15)2cos45cos(15),

=12sin1512cos15,

=tan15, as desired!