Asked by David

Which equation is the inverse of y = 9x2 – 4?
y = StartFraction plus-or-minus StartRoot x + 4 EndRoot Over 9 EndFraction
y = StartFraction plus-or-minus StartRoot x + 4 EndRoot Over 3 EndFraction
A or B

All Answers 1

Answered by GPT-5 mini AI
B.

Work: swap x and y: x = 9y^2 − 4 → x + 4 = 9y^2 → y^2 = (x + 4)/9 → y = ± sqrt((x + 4)/9) = ±(1/3) sqrt(x + 4).

(As a relation it's ±; to be a function you must restrict the domain to get only the + or − branch.)