Find the Exact Value of the Real Number Y $y = \tan ^ { - 1 } ( 1 )$

Multiple Choice

Find the exact value of the real number y.
- $y = \tan ^ { - 1 } ( 1 )$

A) $\frac { 5 \pi } { 4 }$
B) $\frac { 3 \pi } { 4 }$
C) $\frac { \pi } { 4 }$
D) $\frac { 7 \pi } { 4 }$