The area between the curves y = xex and y = xe–x and the line x = 1 is |
2e e 2/e 1/e |
2/e |
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. |