SOLUTION: Find the inverse function using diagrams and test points f(x) = 2x + 1 Select one: a. f ^-1(x) = (x/2) -1 b. f ^-1(x) = (x/2) +1 c. f ^-1(x) = x-1/2 d. f ^-1(x) = x+1/2

Algebra.Com
Question 1093683: Find the inverse function using diagrams and test points
f(x) = 2x + 1
Select one:
a. f ^-1(x) = (x/2) -1
b. f ^-1(x) = (x/2) +1
c. f ^-1(x) = x-1/2
d. f ^-1(x) = x+1/2

Found 2 solutions by josgarithmetic, greenestamps:
Answer by josgarithmetic(39620)   (Show Source): You can put this solution on YOUR website!
Your given function appears graphed like .

If you reflect that line through , then the resulting reflection is .
and the purple line is the inverse for your given f(x).

None of your choices match the inverse of f(x).

Answer by greenestamps(13200)   (Show Source): You can put this solution on YOUR website!

An interesting idea -- to find the inverse of a linear function by using test points. If we find two (x,y) values that satisfy the given equation and switch the x and y values in each pair, then we will have two points that satisfy the inverse function. Then using those two points we can find the equation of the linear function that contains both of them.

But that method won't work for anything other than a linear function....

Okay, so two points that lie on the graph of the given function are (0,1) and (1,3).

Switching the coordinates, we get the point (3,1) and (1,0). A quick calculation shows the slope of that line is 1/2; and then using that slope with either point we can find that the equation of the inverse function is


So the first response you got to your question is right -- none of the answer choices is the correct inverse function.

RELATED QUESTIONS

Find the inverse function using diagrams and test points. 1: f(x) = 2x + 1 2: f(x) =... (answered by rapture)
Identify the inverse of the function f(x)=-7x+2 A) f(x)*-1=x-2/7 B)f(x)*-1=1/7x-2... (answered by edjones)
For each function, graph the function and its inverse. If the inverse is a function,... (answered by MathLover1)
1) Givem the function F:X=6X-2/X, X>0,find: a) F-1(inverse) b) f-1(-1) c)... (answered by Fombitz)
1) Given the function f:x=6X-(2/X), X>0, Find: a) F-1(inverse) b) f-1(-1) c)... (answered by Fombitz)
If f(x)= square root 2x^2-1 and g(x)=x^1/2, find and simplify a) (f+g)(x) b) (f-g)(x) (answered by Alan3354)
Find the inverse. f (x) = √x-8 Select one: a. f ^–1(x) = x^2 + 8, x ≥ 0... (answered by Boreal)
3. If f(x)=square root 2x^2-1 and g(x)=x^1/2, find (and simplify) a) (f+g)(x) b)... (answered by CPhill)
f(x)=1+(3/(x-2)) Find the inverse function... (answered by Fombitz)