The value of of $\int\limits_0^1 xe^x\,dx$ is: |
$\frac{1}{e}$ $e$ 1 -1 |
1 |
The correct answer is Option (3) → 1 Evaluate: $\displaystyle \int_0^1 x e^x \, dx$ Use integration by parts: Let: $u = x \quad \Rightarrow \quad du = dx$ $dv = e^x dx \quad \Rightarrow \quad v = e^x$ Then: $\int x e^x \, dx = x e^x - \int e^x \, dx = x e^x - e^x + C$ Evaluate definite integral: $\int_0^1 x e^x \, dx = \left[ x e^x - e^x \right]_0^1 = (1 \cdot e^1 - e^1) - (0 \cdot e^0 - e^0) = (e - e) - (0 - 1) = 0 - (-1) = 1$ |