composition of functions problem

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sully039
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composition of functions problem

Postby sully039 » Fri Aug 26, 2011 2:56 am

Given that the graph of y=f(x)---> http://imageshack.us/photo/my-images/825/img0305vg.jpg/ and the functions g(x)=2x+1, h(x)=-x+3 and k(x)=(g o f o h)(x), evaluate k(5).

I'm not sure how to solve this problem :confused: so it would help of someone explained how to do this in steps.
So far I have: k(x)=g(f(h(x)))
g(f(h(x)))=g(f(-x+3))
...but now I'm stuck since f(x) doesn't actually have an equation...only some points.

oh and the answer is suppossed to be 1 o.o

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maggiemagnet
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Re: composition of functions problem

Postby maggiemagnet » Fri Aug 26, 2011 11:08 am

sully039 wrote:Given that the graph of y=f(x)---> http://imageshack.us/photo/my-images/825/img0305vg.jpg/ and the functions g(x)=2x+1, h(x)=-x+3 and k(x)=(g o f o h)(x), evaluate k(5).

I'm not sure how to solve this problem :confused: so it would help of someone explained how to do this in steps.

You can get an "in steps" explanation in here. It shows how to work with "only some points", too! You've gotten to "k(5) = g(f(h(5)))". Now start plugging in. When x = 5, what is h(x)? That number is your new "x". Plug that into f(x). Looking at the graph, when x = (whatever h(5) is), what is f(x)? And so forth.
:clap:

sully039
Posts: 16
Joined: Mon Jul 25, 2011 8:33 pm
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Re: composition of functions problem

Postby sully039 » Fri Aug 26, 2011 2:22 pm

Thanks, I got the answer. Your explanation really helped.
:D


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