Evaluate $\int_2^3 7^x\,dx$:
A$294/\ln 7$
B$294 \ln 7$
C$343 - 49$
D$\ln(343/49)$
Answer & Solution
Correct answer: A. $294/\ln 7$
$\int 7^x\,dx = 7^x/\ln 7 + c$. So $[7^x/\ln 7]_2^3 = (7^3 - 7^2)/\ln 7 = (343 - 49)/\ln 7 = 294/\ln 7$.
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