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40 votes
40 votes
Select the correct answer.if flor)21 + 1I –- 4, what is the value of 1-1(3),A.227B. iC.CO103O D.13O E.11

User Darin
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1 Answer

17 votes
17 votes

The inverse funtion of


f(x)=(2x+1)/(x-4)

is


f^(-1)(x)=(4x+1)/(x-2)

We can check this by doing


f(f^(-1)(x))=(2((4x+1)/(x-2))+1)/((4x+1)/(x-2)-4)=((8x+2+x-2)/(x-2))/((4x+1-4x+8)/(x-2))=(9x)/(9)=x

Now that we've confirmed it is the inverse function, we simply evaluate at x=3:


f^(-1)(3)=(4(3)+1)/(3-2)=(12+1)/(1)=13

Thus the answer is D.

User Artsiom Miksiuk
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2.7k points