The region under the graph y=1/2(e^x + e^-x) and between the lines x=-2 and x=2 is rotated about the x-axis. Find the volume of the revolution formed.
Ive got the answer to 49.106. However it is different to the book by about 2 decimla places. I am wondering if i am wrong or what?
by the way 1/2(e^x +e^-x) is also known as cosh(x)
I get 49.15
Without seeing your work I can't tell where the discrepancy might be.
I would guess you may have rounded in the evaluation as you went instead of waiting until the very end to round your result?