Value of functions

[Tony N.]

If f(x)=2x+1 and g(x)=|x+2| what is the value of the following?
g(y), f(x-2), g(2y), f(d), and f(a-1)

Don’t answer all these just one or two.
Do I just replace the x with what’s in the parenthesis so like instead of f(x)=2x+1 I just write f(x)=2x-2+1as the value? I don’t really know to to find the value of a function when you replace the x with another variable g(y). I don’t know how to solve this question at all really, I’m new to advanced algebra.

 

[Deleted member 4993]

If f(x)=2x+1 and g(x)=|x+2| what is the value of the following? g(y), f(x-2), g(2y), f(d), and f(a-1)

Hint: if If f(x)=2x+1 then

replace 'x' with 'a' to get

f(a) = 2a + 1

Please also refer to our submission guideline at: https://www.freemathhelp.com/forum/...ines-from-the-sites-owner.109846/#post-455414

 

[Harry_the_cat]

If f(x)=2x+1 and g(x)=|x+2| what is the value of the following?
g(y), f(x-2), g(2y), f(d), and f(a-1)

Don’t answer all these just one or two.
Do I just replace the x with what’s in the parenthesis so like instead of f(x)=2x+1 I just write f(x)=2x-2+1as the value? I don’t really know to to find the value of a function when you replace the x with another variable g(y). I don’t know how to solve this question at all really, I’m new to advanced algebra.

" instead of f(x)=2x+1 I just write f(x)=2x-2+1as the value?"

I'm assuming here you are talking about the second part f(x-2).

If f(x) = 2x+1 then f(anything) = 2(anything) +1

Yes "you replace the x with what’s in the parenthesis" as you said, BUT brackets are very important!!

So f(x-2) = 2(x-2)+1 =2x- 4+1 = 2x - 3

So use brackets and simplify if necessary.

Have a go at the others and let us see what you can do, so we can help you

 

[Tony N.]

Thank you that helped a lot and I’ll be able to solve the rest.