Answer
Identities can be verified by manipulating each side independently or by separating quotient terms into two terms.
Work Step by Step
Strategy 1:
To verify an identity, each side of the equation is manipulated independently of the other side. So, start with the side containing a more complicated expression; substitute one or more fundamental identities on the more complicated side to rewrite it in a form that is identified on the other side.
Strategy 2: Separate a single term quotient into two terms. That is,
$\frac{a+b}{c}=\frac{a}{c}+\frac{b}{c}$
Example:
$\begin{align}
& \frac{1+\sin x}{\cos x}=\frac{1}{\cos x}+\frac{\sin x}{\cos x} \\
& \frac{1+\sin x}{\cos x}=\sec x+\tan x \\
\end{align}$
Hence, the left-hand side is equal to the right-hand side.
