How To Find The Inverse Of A Function With Fractions

Alright, buckle up buttercups! We're about to dive into the wild, wonderful world of finding the inverse of a function... with fractions! Don't let those fractions scare you. They're just numbers in disguise, ready for an adventure.
Step 1: The Great Switcheroo
First, you've got your original function. Let's say it looks something like this: y = (2x + 1) / 3
. Now, imagine you're at a groovy dance party, and "x" and "y" decide to swap partners! That's exactly what we're gonna do.
Rewrite the equation, but wherever you see a "y," put an "x," and vice versa. So, our equation magically transforms into: x = (2y + 1) / 3
. Easy peasy, lemon squeezy!
Step 2: Unleash the Power of Algebra (Fear Not!)
Now comes the fun part: solving for "y." Think of it like rescuing "y" from a mathematical dungeon. We've got to get it all alone on one side of the equation. It might seem intimidating, but trust me, you've got this!
Getting Rid of the Fraction Fright
See that divided by 3? It's like a tiny fraction monster trying to hold us back. Let's banish it! Multiply both sides of the equation by 3. This gives us: 3x = 2y + 1
.
Isolate That "y"!
Next, we want to get rid of that "+ 1" hanging around with the "2y". Subtract 1 from both sides. Now we have: 3x - 1 = 2y
.
Almost there! "y" is still clinging to that "2." Let's divide both sides by 2. Boom! We get: (3x - 1) / 2 = y
.
Step 3: The Grand Finale (and a Fancy Name)
You've done it! You've solved for "y". Now, let's give our new "y" a super cool name. Instead of just "y," we call it f-1(x) (that's "f inverse of x").
This is the official symbol for the inverse function! So, we can rewrite our equation as: f-1(x) = (3x - 1) / 2
. Ta-da! You are a mathematical wizard!
Example Time: Pizza Delivery Edition
Let's say a pizza place has a special deal where the cost of a pizza (y) is calculated as: y = (x + 2) / 4
, where 'x' is the number of toppings you add. This includes a delivery charge and material charge.
Now, if you know the total cost (x), how do you figure out how many toppings (y) you actually ordered? That's where the inverse function comes in!
First, swap x and y: x = (y + 2) / 4
. Next, multiply both sides by 4: 4x = y + 2
. Then, subtract 2 from both sides: 4x - 2 = y
.
So, the inverse function is: f-1(x) = 4x - 2
. If your pizza cost you $10 (x = 10), then you got 4(10) - 2 = 38 toppings. Maybe that's a little excessive (and definitely overpriced!), but you get the idea!
One Last Tip: Always Double-Check!
The best way to make sure you found the right inverse function is to test it out. Plug a number into your original function, get an answer, and then plug that answer into your inverse function. If you get your original number back, you're golden!
Congratulations! You've conquered the fraction-filled world of inverse functions. Now go forth and invert with confidence!

















