To answer this question we will use a known relation between the sine and the arctangent:
[tex]\sin (\arctan x)=\frac{x}{\sqrt[]{1+x^2}}.[/tex]
Therefore, an equivalent expression to the one given is:
[tex]\frac{x}{\sqrt[]{1+x^2}}\text{.}[/tex]
Answer:
[tex]\frac{x}{\sqrt[]{1+x^2}}\text{.}[/tex]
