Question

If the instructions for a problem ask you to use the smallest possible domain to completely graph two periods of y = 5 + 3 cos 2(x - pi divided by three), what should be used for Xmin and Xmax? Plz explain why because this question is seriously confising me.

Answer 1

Hello,

y=5+3*cos (2(x-π/3))

The function is periodic with periode=2π.


-1<=cos (2(x-π/3))<=1
==>-1*3<=3*cos (2(x-π/3))<=3*1
==>5-3<=5+3cos(2(x-π/3))<=5+3
==>2<= y<=8