Given: AC = 6 1/4 in and CB = 3 1/2 in
Find: The length of AB or AB

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

The sum of two numbers is 12 and their difference is 18 what are the two numbers

A. 90 degrees b. 45 degrees c. 30 degrees d. 120 degrees