How do you find what the points Pi2 0 Pi 1 3pi2 0 2pi 1 Tra

Solution

from comparing the graph of parent function y = cos x with y = 4 cos ( x + pi/5 )

we can see that (pi/2 , 0 ) is transformed to ( pi/2 - pi/5 , 0 ) = ( 3 pi/10 , 0 )

( pi, -1 ) is transformed to ( 4pi/5 , -4 ) since amplitude is changed to 4

( 3pi/2 , 0 ) is transformed to ( 3pi/2 - pi/5 , 0 ) = (13 pi/10 , 0 )

( 2 pi , 1) is transformed to ( 9pi/5 , 4)