Question
Question: Range of f(x) = \(\cos ^ { - 1 } \left( \frac { 1 + x ^ { 2 } } { 2 x } \right) + \sqrt { 2 - x ^ {...
Range of f(x) = cos−1(2x1+x2)+2−x2 is
A
{0,1+2π}
B
{0, 1 + π}
C
{1,1+2π}
D
{1,1+2π}
Answer
{1,1+2π}
Explanation
Solution
is defined if
≤ 1
⇒ x ≠ 0 ⇒ 1 + x2 - 2|x| ≤ 0
⇒ (|x|− 1)2 ≤ 0 ⇒ x = 1, -1
Thus domain of f(x) is {1, -1}. Hence range
is {1, 1 + π}.