### Home > CALC > Chapter 9 > Lesson 9.1.3 > Problem9-41

9-41.

No Calculator! A point is moving along the graph of $y =\operatorname{cos} x$ so that $\frac { d x } { d t } = 3$. Find the rate at which $y$ is changing when $x = \frac { \pi } { 4 }$.