Math  /  Algebra

QuestionIf f(x)=5x+1f(x)=-5 x+1, then f1(x)=f^{-1}(x)= \square
Submit Question

Studdy Solution

STEP 1

1. We are given the function f(x)=5x+1 f(x) = -5x + 1 .
2. We need to find the inverse function, denoted as f1(x) f^{-1}(x) .
3. The function is linear, so its inverse will also be a linear function.
4. The inverse function f1(x) f^{-1}(x) will satisfy the condition f(f1(x))=x f(f^{-1}(x)) = x .

STEP 2

1. Set y=f(x) y = f(x) .
2. Solve for x x in terms of y y .
3. Swap x x and y y to find f1(x) f^{-1}(x) .
4. Verify the inverse function by checking the condition f(f1(x))=x f(f^{-1}(x)) = x .

STEP 3

Set y=f(x) y = f(x) , which gives us:
y=5x+1 y = -5x + 1

STEP 4

Solve for x x in terms of y y . Start by isolating the term with x x :
y1=5x y - 1 = -5x
Divide both sides by 5-5 to solve for x x :
x=y15 x = \frac{y - 1}{-5}

STEP 5

Swap x x and y y to express the inverse function:
y=x15 y = \frac{x - 1}{-5}
Thus, the inverse function is:
f1(x)=x15 f^{-1}(x) = \frac{x - 1}{-5}

STEP 6

Verify the inverse function by checking if f(f1(x))=x f(f^{-1}(x)) = x .
Substitute f1(x) f^{-1}(x) into f(x) f(x) :
f(x15)=5(x15)+1 f\left(\frac{x - 1}{-5}\right) = -5\left(\frac{x - 1}{-5}\right) + 1
Simplify the expression:
=(x1)+1 = (x - 1) + 1 =x = x
Since f(f1(x))=x f(f^{-1}(x)) = x , the inverse function is verified.
The inverse function is:
x15 \boxed{\frac{x - 1}{-5}}

Was this helpful?

Studdy solves anything!

banner

Start learning now

Download Studdy AI Tutor now. Learn with ease and get all help you need to be successful at school.

ParentsInfluencer programContactPolicyTerms
TwitterInstagramFacebookTikTokDiscord