### Home > APCALC > Chapter 7 > Lesson 7.4.4 > Problem 7-219

7-219.

A particle moves along the curve so that its

*‑coordinate increases at the constant rate of*

*changing when*

*?*

(As shown in the diagram at right, is the angle between the segment joining the point to the origin and the

*-axis.)*

What are the opposite and adjacent sides here?

To obtain , use implicit differentiation in terms of

*, since the*

*-coordinate and*

*are changing over time.*