How do you find the equation for the inverse of y=2x+1?

2 Answers
Narad T.
Aug 8, 2017

The inverse is =(x-1)/2

Explanation:

Our equation is

y=2x+1, we have y as a function of x

We need x as a function of y

2x=y-1

x=(y-1)/2

Therefore. the inverse is

y^-1=(x-1)/2

Verification

#yoy^-1=y((x-1)/2)=2*(x-1)/2+1=x#

The inverse of y is the image of y in the line y=x

graph{(y-x)(y-2x-1)(y-x/2+1/2)=0 [-6.24, 6.244, -3.12, 3.12]}

Jim G.
Aug 8, 2017

f^-1(x)=1/2(x-1)

Explanation:

"rearrange making x the subject"

2x+1=y

rArr2x=y-1

rArrx=1/2(y-1)

"expressing the inverse function in terms of x gives"

f^-1(x)=1/2(x-1)

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