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34 votes
34 votes
If f(x)=4x + 3 find f^-1(x)

User Erick Ramirez
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2 Answers

7 votes
7 votes

Answer:

y = (1/4)(x - 3) is the desired inverse function of f(x) = 4x + 3.

Explanation:

Here we're finding the 'inverse function' of the given f(x) = 4x + 3. Follow these steps:

1. Replace the label f(x) with y: y = 4x + 3

2. Interchange x and y: x = 4y + 3

3. Solve this new equation for y: 4y = x - 3, or y = (1/4)(x - 3

User Emaxi
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2.7k points
18 votes
18 votes

Answer:

f^-1(x) = (x-3)/4

Explanation:

The notation f^-1(x) means that you are finding the inverse of the function f(x). To do this, you'll want to swap the "x" and the "y" in the original function, and then solve for y. Here's how:

First, we take the original function and swap the two variables:

y = 4x + 3

x = 4y + 3

Then we subtract 3 from both sides

x - 3 = 4y

Then to get y on its own, we divide both sides by 4.

y = (x-3)/4

Make sure to note that the whole expression x-3 is divided by 4, not just one part of it.

So your new inverse equation is:

f^-1(x) = (x-3)/4

User Nomadictype
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2.7k points