(X Sin X + Cos X ) (Ex + X2 Log X) - Mathematics

(x sin x + cos x ) (ex + x2 log x

Solution

$\text{ Let } u = x \sin x + \cos x; v = e^x + x^2 \log x$
$\text{ Then }, u' = \left[ x\frac{d}{dx}\left( \sin x \right) + \sin x \frac{d}{dx}\left( x \right) \right] - \sin x$
$= x \cos x + \sin x - \sin x$
$= x \cos x$
$v' = e^x + \left[ x^2 \frac{d}{dx}\left( \log x \right) + \log x \frac{d}{dx}\left( x^2 \right) \right]$
$= e^x + x + 2x \log x$

$\text{ Using the product rule }:$
$\frac{d}{dx}\left( uv \right) = u v ' + v u'$
$\frac{d}{dx}\left[ \left( x \sin x + \cos x \right)\left( e^x + x^2 \cos x \right) \right]$
$= \left( x \sin x + \cos x \right)\left( e^x + x + 2x \log x \right) + \left( e^x + x^2 \log x \right) \left( x \cos x \right)$


Concept: The Concept of Derivative - Algebra of Derivative of Functions
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APPEARS IN

RD Sharma Class 11 Mathematics Textbook
Chapter 30 Derivatives
Exercise 30.4 | Q 12 | Page 39