How do you find (dy)/(dx) given xsqrt(y+2)=4?

1 Answer
Mar 9, 2017

dy/dx = -(2(y+2))/x

Explanation:

Differentiate both sides with respect to x using the product rule:

d/dx (xsqrt(y+2)) = d/dx 4

sqrt(y+2) + x/(2sqrt(y+2))dy/dx = 0

+ x/(2sqrt(y+2))dy/dx = -sqrt(y+2)

dy/dx = -(2(y+2))/x

As x > 0 we can also write it as:

dy/dx = -(2xsqrt(y+2)sqrt(y+2))/x^2 = -(8*sqrt(y+2))/x^2