How do you graph y=-csc3theta?

1 Answer
Feb 18, 2018

See below.

Explanation:

y=-csc3theta

=-1/sin(3theta)

Let x=3theta -> y=-1/sinx

Consider: lim_(x->0^+) -1/sinx = -oo

and, lim_(x->0^-) -1/sinx = oo

This cycle is repeated for lim_(x->npi^+) y and lim_(x->npi^-) y forall n in ZZ

Note that y has local maxima of -1 at x=((2n+1)pi)/2 forall n in ZZ and y has local minima of +1 at x=((4n-1)pi)/2 forall n in ZZ

This can be represented graphically below.

graph{-1/sinx [-10, 10, -5, 5]}

Replacing x by 3theta has the effect of decreasing the period by a factor of 3. As shown below.

graph{-1/sin(3x) [-10, 10, -5, 5]}

Hence, the graph above is the graph of y=-csc(3theta)
where theta is shown on the vertical axis.