Can you graph?
1 Answer
We have to know what the cosine graph looks
Min~-1
Max~1
Period=
Amplitude=1
graph{cos(x) [-10, 10, -5, 5]}
Translation form is
A~ Horizontal stretch, amplitude streches by A
B~ Vertical stretch, Period stretches by
C~Vertical translation, x values move over by C
D~Horizontal translation, y values move up by D
But this can't help us until we have y by itself so multiply both sides by
So the 2/3 is the vertical stretch and it stretches the period by 3/2 so the new period is
The
graph{8/9cos(2/3x) [-10, 10, -5, 5]}