Bob currently has $1,000 in a saving account he saves $25 per month he saves the same amount each month and does not take any money out of the account and how many months will boris have 1,450

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