Question

How do you graph `y=3-cosx`?

Answer 1

Plot `cos(x)`
then reflect in the X-axis to get `-cos(x)`
and finally shift all point up `3` units to get `3-cos(x)`

Explanation:

I have assumed that you are familiar with the graph for `color(red)(y=cos(x))`:

Reflecting this in the X-axis causes every `y` coordinate to be come the negative of what it was for `color(grey)(y=cos(x))`;
that is we get `color(red)(y=-cos(x))`

Then adding `3` to every `y` coordinate increases each `y` value of `color(grey)(y=-cos(x))` by `3` to give `color(red)(y=3-cos(x))`