i need help on this problem!!

Find the area of the surface obtained by rotating the curve y=sqrt(4x) from x=0 to x=7 about the x-axis.

Question

i need help on this problem!!

Find the area of the surface obtained by rotating the curve y=sqrt(4x) from x=0 to x=7 about the x-axis.

anonymous · Answer

we can use the shell method, $$\huge \int_{0}^{7}2pi(x)(\sqrt{4x})$$

anonymous · Answer

it says the answer is wrong!!
i thought we needed to use the surface area formula

anonymous · Answer

Oh snap my bad, i though your were looking for the area of revilution , sorry

anonymous · Answer

oh its ok cuz i was typing int he answer different ways and saw it needed the are of the surface

anonymous · Answer

well, all we need to do is find the derivtive of the the function , the deriviatie in this case is |dw:1323905889920:dw|

anonymous · Answer

now we square this and get, 1/x