How do you sketch one cycle of y=-cotx?

1 Answer
Aug 9, 2018

See explanation and graphs.

Explanation:

y = - cot x = - cos x/sin x,

x ne ( asymptotic ) zeros of the denominator

kpi, k = 0, +-1, +-2, +-3, ....

The period = period of the reciprocal ( - tan x ) = pi

= the space between consecutive asymptotes, x = kpi.

The amplitude is 1/2 pi.

See graph, depicting all these aspects.
graph{(y sin x + cos x)( x +.0001y) ( x- pi +.0001y)=0[ 0 pi -pi/4 pi/4]}

Here, 1-cycle graph is precisely given by the inverse

x = - arctan ( 1/y ), x in [ - pi/2, pi/2 ].

graph{x + arctan(1/y)=0}.

This phenomenon is attributed to the constraint on the range of arctan values as [ - pi/2, pi/2 ].