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Question 114947: I know it looks like it's two questions but according my book it is one. Please help me.
A function is defined by f(x) = 2x - 4
f (x + h)
f (3)
Answer by bucky(2189)   (Show Source):
You can put this solution on YOUR website! I'm not sure what your book means when it says this is one problem. But let's discuss how
to do this problem.
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We are given:
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f(x) = 2x - 4
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Let's do the last one first. We are asked to find f(3). All this is telling us to do is
to go to the given equation, substitute 3 wherever you see x, and then simplify.
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So to find f(3) we start with the given equation:
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f(x) = 2x - 4
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Then we substitute into that equation a 3 for every x and we get:
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f(3) = 2*3 - 4
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Then we simplify the right side by multiplying the 2 times 3 to get 6 which makes the equation:
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f(3) = 6 - 4
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and finally we subtract the 4 from the 6 to get:
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f(3) = 2
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That's the answer for f(3). To get f(x + h) we do the same thing, only this time we substitute
x + h for every x in the given equation. So start with the given equation:
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f(x) = 2x - 4
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Now replace every x in that equation with x + h and we get:
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f(x + h) = 2*(x + h) - 4
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Now multiply out the right side to get:
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f(x + h) = 2x + 2h - 4
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and this is as much as we can simplify the right side. So the answer is:
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f(x + h) = 2x + 2h - 4
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Hope this helps you to understand what the problem is asking you to do, and helps you
to understand what you do to solve problems such as this.
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