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## Homework Statement

Find the surface area of the cone z=3x^2+y^2and above a region in the xy-plane with area 4.

## Homework Equations

double integral sqrt( (dz/dx)^2 + (dz/dy)^2 +1)

## The Attempt at a Solution

I was able to simplify the equation, I just don't know what to do with the area part of the question:

dbl int sqrt ( (3x/sqrt(x^2+y^2))^2 + (3y/sqrt(x^2+y^2))^2 + 1)

dbl int sqrt (9 (x^2+y^2)/(x^2+y^2) + 1 )

dbl int sqrt (10)

change into polar coordinates

integral [0-1] dtheta integral [0-2pi] sqrt(10) r dr

= 1*2pi sqrt(10)

what am I doing wrong?