Question

What is the range of the function y = RootIndex 3 StartRoot x + 8 EndRoot?
A)Negative infinity less-than y less-than infinity
B)Negative 8 less-than y less-than infinity
C)0 less-than-or-equal-to y less-than infinity
D)2 less-than-or-equal-to y less-than infinity

Answer 1

A) Negative infinity < y < infinity

Reason: For any real y, choose x = y^3 − 8. Then y = ∛(x + 8), so every real y occurs. Thus the range is all real numbers.