Given
[tex]\tan (\frac{3\pi}{4})[/tex]In radian
[tex]\pi=180^o[/tex]Substitute the value into the given expression
[tex]\tan (\frac{13\pi}{4})=\tan (\frac{13(180)}{4})[/tex]Simplify the expression
[tex]\tan (\frac{13(180)}{4})=\tan (585)[/tex]By using calculator
[tex]\tan (585)=1[/tex]Therefore the answer is
[tex]\tan (\frac{13\pi}{4})=1[/tex]