using shell method what am i doing wrong

[calcnoob145]

here is my problem and my work the answer is 4pi but i get 12pi when i do my work where am i going wrong

 

[Deleted member 4993]

here is my problem and my work the answer is 4pi but i get 12pi when i do my work where am i going wrong

View attachment 2796

On 3rd line, you are taking 2π*x out of the integral sign.

You cannot take x out of the integration sign.

 

[calcnoob145]

so take out the 2pi but leave the x in the integral

 

[Deleted member 4993]

so take out the 2pi but leave the x in the integral

Yes....