### All GRE Math Resources

## Example Questions

### Example Question #2541 : Act Math

Find the inverse equation of:

**Possible Answers:**

**Correct answer:**

To solve for an inverse, we switch x and y and solve for y. Doing so yields:

### Example Question #1 : How To Find Inverse Variation

Find the inverse equation of .

**Possible Answers:**

**Correct answer:**

1. Switch the and variables in the above equation.

2. Solve for :

### Example Question #2 : How To Find Inverse Variation

When , .

When , .

If varies inversely with , what is the value of when ?

**Possible Answers:**

**Correct answer:**

If varies inversely with , .

1. Using any of the two combinations given, solve for :

Using :

2. Use your new equation and solve when :

### Example Question #2 : Algebraic Fractions

x |
y |

If varies inversely with , what is the value of ?

**Possible Answers:**

**Correct answer:**

An inverse variation is a function in the form: or , where is not equal to 0.

Substitute each in .

Therefore, the constant of variation, , must equal 24. If varies inversely as , must equal 24. Solve for .

### Example Question #1 : Algebraic Fractions

and vary inversely. When , . When , . What does equal when ?

**Possible Answers:**

**Correct answer:**

Because we know and vary inversely, we know that for some .

When , . .

When , . .

Therefore, when , we have so