The area between the curves y = xex and y = xe–x and the line x = 1 is
Answer & explanation
Correct answer: option 3
The line x = 1 meets the curves in A(1, e) and B(1, 1/e). Both the curves pass through the origin.
The required area
$A=\int\limits_0^1(y_1-y_2)dx=\int\limits_0^1(xe^x-xe^{-x})dx$
$=[x\{e^x+e^{-x}\}]_0^1-\int\limits_0^1(e^x+e^{-x}).1dx$
$=(e+\frac{1}{e})-[e^x+e^{-x}]_0^1=(e+\frac{1}{e})-(e-\frac{1}{e})=\frac{2}{e}$ sq. units.
Hence (C) is the correct answer.