2. Helen can type 120 words in 4 minutes. How many words can she type in 6 minutes? *
A 30 words
B 240 words
C 480 words
D 180 words

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