### Home > CALC > Chapter 8 > Lesson 8.2.1 > Problem8-67

8-67.

Find $\frac { d y } { d x }$ for the following functions. Then evaluate the derivative at the given point.

1. $\frac { 2 } { x } - \frac { 1 } { y }= 1$ ; $(1,1)$

$-2x^{-2}+y^{-2}y^\prime=0$

$-2(1)^{-2}+(1)^{-2}y^\prime=0$
Now solve for $y^\prime$.

1. $x^2y − y^3 = 8$; $(−3, 1)$

$2xy+x^2y^\prime-3y^2y^\prime=0$