### Home > APCALC > Chapter 6 > Lesson 6.1.4 > Problem 6-47

6-47.

Sketch a graph of . Predict the slopes of the tangent lines at

*. Then, confirm this algebraically by differentiating. (Hint: Solve for*

*first.)*

Sketch the graph (it's a circle). Then sketch the tangents (they are horizontal). What do you predict the slope of the tangents to be?

Confirm your prediction by evaluating the derivative of the circle at .

Note: Before differentiating, solve for