How do you graph #y=3 cos (x/5)#?

1 Answer
Aug 18, 2016

See explanation

Explanation:

The standardised #cos(theta)# has a max of +1 and a min of -1.

Thus #3xxcos(theta)# changes this to a max of 3 and a min of -3.
Su the up and down is increased by a factor of 3.

The #x/5# reads a point on graph of #cos(x/5)# and plots it at #x#

Consequently #x/5# opens up the plot of #cos(x)# like stretching a spring and in doing so expanding it horizontally by a factor of 5.

#color(purple)("The graph below uses radian measure for the x-axis")#

Tony B