Question
Question: Range of f(x) = sin<sup>-1</sup>x + tan<sup>-1</sup>x + cos<sup>−1</sup>x is...
Range of f(x) = sin-1x + tan-1x + cos−1x is
A
(0,23π)
B
(2π,23π)
C
(−2π,23π]
D
[4π,43π]
Answer
[4π,43π]
Explanation
Solution
Clearly the domain of the function is [-1, 1]. We know that tan−1 x ∈ [−4π,4π] for
x ∈ [-1, 1]. Thus range is [4π,43π]