### Home > CALC > Chapter 4 > Lesson 4.4.2 > Problem 4-140

4-140.

Find the equation of the line that is:

Tangent to the function

at .Write the equation of the tangent line in point-slope form.

We know that the point of tangency happens at

. Evaluate the function,, to find the point.

Evaluate the derivative,, to find the slope.Normal to the tangent line at

.Definition: A 'normal line' is perpendicular to a tangent line at the point of tangency.