Evaluate cot((13pi)/4)

$\cot (\frac{13 π}{4})$

Subtract full rotations of $2 π$ until the angle is greater than or equal to $0$ and less than $2 π$ .

$\cot (\frac{5 π}{4})$

Apply the reference angle by finding the angle with equivalent trig values in the first quadrant.

$\cot (\frac{π}{4})$

The exact value of $\cot (\frac{π}{4})$ is $1$ .

$1$