Use the cofunctions of complementary angles to complete the

Use the cofunctions of complementary angles to complete the relationship

Tan(pi/4)=Cot( )

tan (pi/4)

The value of trigo function of an angle is equal to the value of the cofunction of the complement of angle

Therefore tan(pi/4)=cot(pi/2 -pi/4)

tan(pi/4) = cot(pi/4)