Raquel got 4 out of 5 questions correct on her english quiz and is convinced that this equates to a score of 90%. show raquel’s what percentage 4 out of 5 actually quells , being sure to use cross products to prove your answer

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