Question

How do I simplify:

S=2 Pi r squared + 2 Pi r h

Then how do I make h the subject

Then what is the value of h if S=50 and r=3

Thanks

Answer 1

`S=2\pi r^2+2\pi rh\\\\2\pi rh+2\pi r^2=S\ \ \ \ \ \ |subtract\ 2\pi r^2\ from\ both\ sides\\\\2\pi rh=S-2\pi r^2\ \ \ \ \ \ \ |divide\ both\ sides\ by\ 2\pi r\\\\\boxed{h=(S-2\pi r^2)/(2\pi r)}\\\\S=50;\ r=3\\\\\boxed{h=(50-2\pi\cdot3^2)/(2\pi\cdot3)=(50-2\pi\cdot9)/(6\pi)=(50-18\pi)/(6\pi)} < 0-no\ sense\\\\I\ think...\ S\ not\ equal\ 50!!!`