Rubin has 6 rolls of pennies containing 50 coins each

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

On a piece of paper graph f(x)=5•(0.4)^x

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?