Start on the left side.
Apply the reciprocal identity to .
Multiply the numerator and denominator of the complex fraction by .
Multiply by .
Combine.
Apply the distributive property.
Cancel the common factor of .
Cancel the common factor.
Rewrite the expression.
Simplify the numerator.
Move to the left of .
Rewrite as .
Factor out of .
Factor out of .
Factor out of .
Cancel the common factor of .
Rewrite as .
Because the two sides have been shown to be equivalent, the equation is an identity.
is an identity
Verify the Identity (sec(x)-1)/(1-cos(x))=sec(x)