Verify the identity: (secr - tan c)? - 1 - sin c 1 + sinc To verify the identity, start with the left side and transform it to look like the right side. First use reciprocal and quotient identities. (secr - tan r)' = Combine the fractions. Now square the top and bottom separately. Do not use any identities in this step. - 2 sinc + sin r Rewrite the denominator by applying a Pythagorean identity. - 2 sinc + sin r Factor the numerator and denominator. Simplify your