Which equation is the inverse of [tex]y = 7x^2 - 10[/tex]?

A. [tex]y = \frac{\pm \sqrt{x+10}}{7}[/tex]

B. [tex]y = \pm \sqrt{\frac{x+10}{7}}[/tex]

C. [tex]y = \pm \sqrt{\frac{x}{7} + 10}[/tex]

D. [tex]y = \frac{\pm \sqrt{x}}{7} \pm \frac{\sqrt{10}}{7}[/tex]



Answer :

To find the inverse of the given equation [tex]\(y = 7x^2 - 10\)[/tex], let's follow the steps in detail:

1. Start with the given equation:
[tex]\[ y = 7x^2 - 10 \][/tex]

2. Swap [tex]\(x\)[/tex] and [tex]\(y\)[/tex]:
Inverse of a function means swapping the roles of [tex]\(x\)[/tex] and [tex]\(y\)[/tex].
[tex]\[ x = 7y^2 - 10 \][/tex]

3. Solve for [tex]\(y\)[/tex]:
Our goal now is to isolate [tex]\(y\)[/tex].

a. Add 10 to both sides to move the constant term to the left side:
[tex]\[ x + 10 = 7y^2 \][/tex]

b. Divide both sides by 7 to isolate the term with [tex]\(y\)[/tex]:
[tex]\[ \frac{x + 10}{7} = y^2 \][/tex]

c. Take the square root of both sides. Remember, taking the square root gives both positive and negative solutions:
[tex]\[ y = \pm \sqrt{\frac{x + 10}{7}} \][/tex]

Therefore, the inverse of the function [tex]\(y = 7x^2 - 10\)[/tex] is:
[tex]\[ y = \pm \sqrt{\frac{x+10}{7}} \][/tex]

The correct answer from the given choices is:
[tex]\[ y = \pm \sqrt{\frac{x+10}{7}} \][/tex]