Question
Differentiate the following functions by the product rule and the other method and verify that the answer from both the methods is the same.

$(\text{x}+2)(\text{x}+3)$

Answer

Let $\text{u}=(\text{x}+2);\text{v}=(\text{x}+3)$

Then, $\text{u}'=1;\text{v}'=1$

Using the product rule:

$\frac{\text{d}}{\text{dx}}(\text{uv})=\text{uv}'+\text{vu}'$

$\frac{\text{d}}{\text{dx}}[(\text{x}+2)(\text{x}+3)]=(\text{x}+2)1+(\text{x}+3)1$

$=\text{x}+2+\text{x}+3$

$=\text{2x}+5$

Alternate method

$\frac{\text{d}}{\text{dx}}[​(\text{x}+2)(\text{x}+3)]$

$=\frac{\text{d}}{\text{dx}}(\text{x}^2+\text{5x}+6)$

$=\text{2x}+5$

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