Posted by **Janie** on Tuesday, August 24, 2010 at 2:00am.

if f(x) = (x/7)-3 find f^-1(x)

I'm completely lost! Help

- CONFUSED~MATH -
**drwls**, Tuesday, August 24, 2010 at 2:09am
The inverse function f^-1(x) gives you back x when you input y = f(x) as the independent variable.

Start with y = (x/7)-3

y + 3 = x/7

x = 7y + 21

Since you are using x as the independent variable of the inverse function, you have to switch x and y in the equation above.

The inverse function is therefore

f^-1(x) = 7x + 21

Check: Use (7x +21) as "x" in the f(x) equation, and you get x back.

## Answer this Question

## Related Questions

- math - 32x^2y-64xy-4x^3y. When I factored out the GCF, I got 4. When I try to ...
- Math - Find the following. Assume the variables can represent any real number...
- confused in math - 1.20 with a line over 20 convert decimal to fraction, step ...
- Math- Completely confused! - Simplify each expression (where possible) and ...
- business math - How do you know which rule to use when it doesn't specify? All ...
- Calculus - If position is given by p(t)=t^2 +1, find the velocity v(t) at t = 2...
- Algebra - Okay i have a few function questions im gonna post. Im completely ...
- chemistry desperately - i am completely lost, i confused myself. i need to find ...
- Chemistry - Dr. Bob222 Please don't get frustrated with me, I'm really trying to...
- Statistics - For a distribution in which the mean is 100 and the standard ...