Question

which equation is the inverse of (y = 100 - x^2)?

• (y = \pm \sqrt{100 - x})
• (y = 10 \pm \sqrt{x})
• (y = 100 \pm \sqrt{x})
• (y = \pm \sqrt{x - 100})

Explanation:

Interchange the variables x and y

$$ x = 100 - y^2 $$

Isolate the term with y

$$ y^2 = 100 - x $$

Solve for y using the square root property

$$ y = \pm\sqrt{100 - x} $$

Answer:

• (A) \(y = \pm\sqrt{100 - x}\) (Correct answer)
• (B) \(y = 10 \pm \sqrt{x}\)
• (C) \(y = 100 \pm \sqrt{x}\)
• (D) \(y = \pm\sqrt{x - 100}\)