Hi please help me with my math homework​

The reflexive property of congruence lets you say that ∠pqr ≅

Check all that apply. f is a function. f is a one-to-one function. c is a function. c is a one-to-one function.

Which sum or difference identity would you use to verify that cos (180° - q) = -cos q? a.) sin (a -b) = sin a cos b – cos a sin b b.) cos (a -b) = cos a cos b – sin a sin b c.) cos (a -b) = cos a cosb + sin a sin b d.) sin (a + b) = sin a cos b + cos a sin b