Question

The domain of $\cos^{-1} \sqrt{2x}$ is

• A. [-1, 1]
• B. [-1/2, 1/2]
• C. [0, 1/2]
• D. (1, 1/2)

Answer 1

Answer: (C)

[0, 1/2]

Answer 2

$0 \le\sqrt{2x} \le 1 \Rightarrow 0 \le2x \le 1 \Rightarrow 0 \le x \le 1/2$