Solve for the indicated variable:

A = 2(pi)r^2 + 2(pi)rh, for positive r
(and by pi i mean 3.14...)

This is what I have so far:

A = 2pi(r^2+rh)
A/2pi=r^2 + rh

?

Thanks!

1 answer

isn't it a quadratic?

r^2 + rh - A/2PI =0
ax^2+bx+c=0

r= (-h +-sqrt(h^2+4A/2PI))/2