# What is the equation of the tangent line of # f(x)=sinpix # at # x=3 #?

##### 1 Answer

Dec 30, 2015

#### Explanation:

graph{sin(pix) [-10, 10, -5, 5]}

To construct a straight line, one needs either two points, or a point and the gradient. In this case, the latter would be more appropriate.

We know that the line passes through the point

We know that the gradient of the line is

Equation of tangent line:

graph{pi(3-x) [-10, 10, -5, 5]}