1. Trig problem

Can someone solve this problem ? I'm stuck ...

$tan^{2}36\times tan^{2}72=5$

2. $
tan^{2}36\times tan^{2}72=5
$

ok cannot factor since it is x not +

3. I dont think you can do that... how about :
$\left ( tan36\times tan72 \right )^{2}$
$\left ( \frac{sin36\times sin72}{cos36\times cos72} \right )^{2}$

4. I'm sorry for double posting but i can't return your PM.
Isn't it the same as :
$\left ( xy \right )^{2}=x^{2}y^{2}$