Question

Need help finding the integrand, I tried 1/x but it's not working. MEDALS to all who attempt <3

Answer 1

the limit of reimann sum is ln13 - ln6
so
\[\int\limits_a^{a+7} f(x) dx = F(a+7) - F(a) = \ln 13 -\ln 6\]
\[F(x) = \ln [6 + (x-a)]\]
taking derivative
\[f(x) = \frac{1}{6 +(x-a)}\]
for your problem you chose a=10
the integrand then would be
\[f(x) = \frac{1}{x-4}\]