How do you graph y=tan2x and include two full periods?

1 Answer
Mar 20, 2017

Create a normal tan graph:
graph{tan(x) [-0.5, 6.29, -4, 4]}
(If you don't know how, then either think of how tan changes as the angle of the triangle increases from zero, or remember this chart:

0 : 0
π4 : 1
π2 : undefined (goes off to infinity)
3π4 : 1
π : 0
Repeat this at least twice.)

Then compress it in the horizontal by a factor of two (because of the 2x in the tan:
graph{tan(2x) [-0.5, 6.29, -4, 4]}
Then flip it on the vertical (because of the negative sign):
graph{-tan(2x) [-0.5, 6.29, -4, 4]}

The graph must show at least π, since the period of tan(x) is pi, which was divided in two by the 2x inside the tan, then multiplied because you need to show two periods