The correct option is C π4,3π4
y=sin−1x+tan−1x+sec−1x
Domain of sin−1xis−1≤x≤1, of tan−1xis−∞<x<∞ of sec−1xisx≤−1 or x≥1.
∴ Domain of the function is x = {- 1, 1}
∴ Value of y=sin−1(−1)+tan−1(−1)+sec−1(−1)
i.e., −π2−π4+π=π4
and sin−1(1)+tan−1(1)+sec−1(1)
i.e., π2+π4+0=3π4
Hence set of values of y=π4,3π4