Question #e30a3

1 Answer
Jan 21, 2018

#b=-13.156# or #b=2.4311# or #b=10.725#

Explanation:

#int_(0)^(b)(49-x^2)dx=343/3#

First, let's integrate this expression.

#343/3=[49x-1/3x^3]_0^b"#

#343/3=(49b-1/3b^3)-0#

#1/3b^3-49b+343/3=0#

#b^3-147b+343=0#

I'm not sure how to solve this cubic; at this point I used wolfram alpha to solve that

#b=-13.156# or #b=2.4311# or #b=10.725#