<u>Answer:</u>
The basic identity used is .
<u>Solution: </u>
In this problem some of the basic trigonometric identities are used to prove the given expression.
Let’s first take the LHS:
Step one:
The sum of squares of Sine and Cosine is 1 which is:
On substituting the above identity in the given expression, we get,
Step two:
The reciprocal of cosine is secant which is:
On substituting the above identity in equation (1), we get,
Thus, RHS is obtained.
Using the identity , the given expression is verified.