Multiply x to (-y) then x to (z)
mean x(-y)+ x(z)
plug in the variable given
(-1)(-(-2)+5)
-2-5=-7
7 weight exactly the same, therefore the 8th golf ball doesnt weigh the same as the 7. so the 8th ball is slightly lighter
The vertex of the equation is ( -2 , -2 )
The axis of symmetry is x= - 2
Double angle identity for sine:


Factorize the left side.

Pythagorean identity:


so that
