Question

Find the range of the quadratic function.

y= 3x2 – 18x+ 23
Write your answer as an inequality using x or y as appropriate.
Or, you may instead click on "Empty set" or "All reals" as the answer.

Answer 1

-4 ≤ y <∞.

Explanation:

y = 3x² - 18x + 23

= 3(x² - 6x) + 23

= 3(x² - 6x + 9) - 27 + 23

= 3(x - 3)² - 4 ≥ -4

So the range is -4 ≤ y <∞.