A
B
C
D
Explanation
Correct answer: B.
Choice B is correct. The value of is the value of when . It's given that the function is defined by . Substituting for in this equation yields . Since the positive square root of is , it follows that this equation can be rewritten as , or . Therefore, the value of is .
Desmos solution:
Enter in Desmos:
Reviewed and rewritten by CookSAT
Why the other choices are wrong
Choice A
Choice A is incorrect and may result from conceptual or calculation errors.
Choice C
Choice C is incorrect. This is the value of , not .
Choice D
Choice D is incorrect. This is the value of , not .