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Guy I'm in serious need for help. I seriously don't know how to do f^-1(x) and all that.

 

f(x) = x - 3 and g(x) = 2x + 1 find g(f^-1 (2)) 

 

I want steps please. There are many other problems like this so I need to understand the rules and basics. 

Thankyou <3

 Mar 15, 2016

Best Answer 

 #1
avatar+129852 
+10

f(x) = x - 3 and g(x) = 2x + 1 find g(f^-1 (2)) 

 

We need to find the inverse function for f

 

f(x)  = x - 3      let  f(x)   = y

 

y = x - 3       add 3 to both sides

 

y  + 3  = x      switch   x and y

 

x + 3  = y    and, for y, write  f-1(x)

 

f-1(x)  = x + 3

 

So

 

f-1 (2)   =   -2 + 3    = 1

 

So

 

g ( f-1(2) )  =  g (1)  = 2(1) + 1   =  3

 

 

cool cool cool

 Mar 15, 2016
 #1
avatar+129852 
+10
Best Answer

f(x) = x - 3 and g(x) = 2x + 1 find g(f^-1 (2)) 

 

We need to find the inverse function for f

 

f(x)  = x - 3      let  f(x)   = y

 

y = x - 3       add 3 to both sides

 

y  + 3  = x      switch   x and y

 

x + 3  = y    and, for y, write  f-1(x)

 

f-1(x)  = x + 3

 

So

 

f-1 (2)   =   -2 + 3    = 1

 

So

 

g ( f-1(2) )  =  g (1)  = 2(1) + 1   =  3

 

 

cool cool cool

CPhill Mar 15, 2016
 #2
avatar+99 
0

Thanks so much CPhill <3 you always got such clear steps :3

lekRJtj  Mar 16, 2016

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