What is the domain of y=-tan^2(x) ?

1 Answer
Jul 23, 2018

x ne ( 2 k + 1 ) pi/4, k = 0, +-1, +-2, +-3. .... See graph.

Explanation:

The asymptotes are x = zeros of the denominator cos 2x,

x = ( 2 k + 1 ) pi / 4, k = 0, +-1, +-2, +-3. ...
So, x ne ( 2 k + 1 ) pi / 4, k = 0, +-1, +-2, +-3. ...

graph{(x-pi/4+0.01y)(y-tan(2x)) =0[-4 4 -2 2]}

One asymptote x = pi/4 is marked.

The space in between the asympyote and the nearby branch of the

graph darr as abs y uarr but never becomes 0. So this x is not

in the graph..