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#1 2006-10-12 05:14:42

unique
Member
Registered: 2006-10-04
Posts: 419

right?

find the inverse function of
y =  2x + 2

original function
y = 2x + 2

rearranged
2x = y - 2

solved for x
x = 1/2y - 1/2

inverse function changed x to y and y to x
y = 1/2x - 1/2

correct
yes no?
downup


Desi
Raat Key Rani !

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#2 2006-10-12 05:29:04

polylog
Member
Registered: 2006-09-28
Posts: 162

Re: right?

unique wrote:

solved for x
2x = y - 2
x = 1/2y - 1/2

This part is not right:
2/2 = 1 not 1/2

wink

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#3 2006-10-12 05:42:59

unique
Member
Registered: 2006-10-04
Posts: 419

Re: right?

ok so the inverse is?
if
2/2 = 1

so
x = y - 1
then
y = x - 1 as inverse ??


Desi
Raat Key Rani !

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#4 2006-10-12 05:53:55

mathsyperson
Moderator
Registered: 2005-06-22
Posts: 4,900

Re: right?

Is that a completely new question?
x = y-1

Add one to both sides: x+1 = y.

Therefore, the inverse is x = y+1.

With the first question, you almost had it.
You said it was y = 1/2x - 1/2 and it was actually y = 1/2x - 1.

Although saying y = x/2 -1 is neater.


Why did the vector cross the road?
It wanted to be normal.

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