How can I simplify $\sqrt{3^2 + 3^2\tan^2\theta}$? $$\sqrt{3^2 + 3^2\tan^2\theta}$$ 

$$ = (3)(3\tan\theta) = 9\tan\theta $$ 

I've simplified it like this but I'm not sure if that's correct.
$$\begin{align} \sqrt{3^2 + 3^2\tan^2\theta} &amp;= \sqrt{9(1+\tan^2 \theta)} \\ 
&amp; = \sqrt 9 \cdot \sqrt {1 + \tan^2 \theta} \\ 
&amp; = 3\sqrt{\sec^2\theta} \\
&amp;= 3|\sec \theta| \end{align}$$
You have

$$\sqrt{9(1-tan^2(x)} = \sqrt{9 \sec^2(x)} = 3\sec(x).$$