Question
Differentiate the following function with respect to x:

$(1+\text{x}^2)\cos\text{x}$

Answer

Let $\text{u}=(1+\text{x}^2);\text{v}=\cos\text{x}$

Then, $\text{u}'=\text{2x};\text{v}'=-\sin\text{x}$

Using the product rule:

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

$\frac{\text{d}}{\text{dx}}=[(1+\text{x}^2)\cos\text{x}]=(1+\text{x}^2)(-\sin\text{x})+(\cos\text{x})(\text{2x})$

$=-\sin\text{x}-\text{x}^2\sin\text{x}+\text{2x}\cos\text{x}$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free