Establish the identity:
tan u - sec u = - cos u / (1 + sin u)
Write the left side in terms of sine and cosine.
tan u - sec u =
Simplify by writing the expression from the previous step over a common denominator.
/ cos u
Rewrite the expression from the previous step by multiplying the numerator and denominator by sin u + 1.
/ cos u( sin u + 1) (Simplify your answer.)
Write the numerator of the expression from the previous step in terms of cosine.
/ cos u( sin u + 1)
The fraction from the previous step then simplifies to - cos u / (1 + sin u) using what?
A. Cancellation Property
B. Reciprocal Identity
C. Pythagorean Identity
D. Quotient Identity
E. Even-Odd Identity