This is not a programming problem, the problem is that you do not know about trig functions. The tangent function is discontinuous in PI/2 + n*PI, so you should break it to pieces at those intervals.

Graphing linear functions Graphing linear functions This section focuses on the key features and methods for working with linear graphs. It demonstrates how to sketch graphs from rules, derive rules ...

Using the pull-down menus, select values for a, b, c, and d. The graph of the function will be updated automatically. Selecting the "show base function" option causes the basic function (with a = b = ...

Revise how to recognise and determine the equation of a quadratic function from its graph. BBC Bitesize Scotland revision for SQA National 5 Maths.

GCSE WJEC Functions - Higher only – WJEC Functions Functions of graphs can be transformed to show shifts and reflections. Graphic designers and 3D modellers use transformations of graphs to ...