CPM Homework Help : APCALC Problem 9-64

No calculator! Determine the slope of the curve $x \cos(y) = xy + 1$ at the point $(1, 0)$ . Compute without a calculator

Steps:

First: Implicitly differentiate: $\cos(y)-x\sin(y)y^\prime=y+xy^\prime$

Second: Solve for $y^\prime$ .

Third: Evaluate the equation for $x = 1$ and $y = 0$ .