Periodic Functions

Remember that cot D = adjacent side/opposite side (cot D = b/a)

What happens as ∠ D goes to 180⁰(Think of the triangle as a reference triangle)?

Side a goes to zero and hence there is an asymptote at 180^o ( π)
What happens to side b as ∠ D goes to 270⁰ ? Does b equal zero?

Yes. So the cot graph will intercept the x axis at 270⁰ (4,712388... radians).

Remember with trig functions such as cot D = b/a the ∠D   is measured on the horizontal axis
and b/a is the height above the x-axis. If this height is zero then the graph intercepts the x axis.

So again what happens at 0⁰, 90⁰, 180⁰, 270⁰ and 360⁰ to the cotangent?

return to the graph of the cot

on to the graph of the csc

return PCTC