# Find the differentiation of f(x) = x2.ex at x = 1

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Find the differentiation of f(x) = x2.ex at x = 1

1.  2e
2. 3e
3. e
4. None of these

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Correct Answer - Option 2 : 3e

Concept:

$\rm \frac{\mathrm{d} (x^{n})}{\mathrm{d} x} = nx^{n-1}$

$\rm \frac{\mathrm{d} (uv)}{\mathrm{d} x} = u\frac{\mathrm{d} v}{\mathrm{d} x} + v \frac{\mathrm{d} u}{\mathrm{d} x}$

$\rm \frac{\mathrm{d} (e^{x})}{\mathrm{d} x} = e^{x}$

Calculation:

Given: f(x) = x2.ex

Now, f'(x) = $\rm \frac{\mathrm{d} (x^{2}e^{x})}{\mathrm{d} x}$

By chain rule ,

⇒ $\rm \frac{\mathrm{d} (x^{2}e^{x})}{\mathrm{d} x} = e^{x}\frac{\mathrm{d} (x^{2})}{\mathrm{d} x} + x^{2} \frac{\mathrm{d} (e^{x})}{\mathrm{d} x}$

= ex2x +x2  ex

= xex(x + 2)

At x = 1;

f'(x)|x=1 = 3e