Question

Question 6: Find the principal value of tan¯¹ (–1)

Class 12 - Math - Inverse Trigonometric Functions

Answer 1

Let tan−1 (−1) = ∅.
Then, tan∅ = -1 =>
-tan ( π /4 ) = tan (- π /4 )
We know that the range of the principal value branch of tan−¹ is (- π /2 , π /2 ) and tan (- π /4 ) = -1

Therefore, the principal value of
tan−¹(−1) is - π /4 .