You don't have to be accurate to do the problem, as long as you can understand it.

When drawing, I usually draw the negative semi-axis, that is, the positive semi-axis has 1 period, and the negative semi-axis has a period (both positive and negative).

The image of the tangent function is a monotonically increasing odd function.

On the image of trigonometric function

Take -2π, -3π/2,-π, -π/2, 0, π/2, π, 3π/2, 2π~ on the X-axis.

Be sure to write when you do the problem, unless the domain is R.