Question

functions f an g defined as f(x)=2x-5 an g(x)=x[2]+3 what is f(4) gf(4) an the inverse of f (x)

Answer 1

help me please

Answer 2

is this the function for g?
\[g(x) = x^{2}+3\]

Answer 3

i dont know that why am askin

Answer 4

Anjalie: What joemath is doing is asking if that's what you meant when you posted the question. What you wrote actually doesn't make mathematical sense... You'll have to help him understand what the question looks like if you want him to help you.

Answer 5

or okay yes thank you

Answer 6

im just gonna solve it with what im assuming the function to be. First problem:
To compute f(4), you take the function f, and everywhere you see an x, plug in a 4:
\[f(x) = 2x-5 \Rightarrow f(4) = 2(4)-5 \Rightarrow f(4) = 8-5 = 3 \]
So f(4) = 3.

Answer 7

Gonna assume the gf(4) means g(f(4)) (although it could mean something else). We already figured out that f(4) = 3, so we just need g(3):
\[g(3) = (3)^{2}+3 = 9+3 = 12\]
so gf(4) = 12

Answer 8

ok thank you so much

Answer 9

For the inverse of f, change the 'f(x)' to a 'y', and solve for x:
\[f(x) = 2x-5 \Rightarrow y = 2x-5 \Rightarrow y+5 = 2x\Rightarrow \frac{y+5}{2} = x\]
Thus f inverse is:
\[f^{-1}(y) = \frac{y+5}{2}\]

Answer 10

ok thank you so much