Problema Solution
The regular price of a computer is x dollars. Let f(x)=x-400 and g(x)= 0.75x.
Describe what the functions f and g model in term of the price of the computer.
Find (f º g)(x) and describe what this models in terms of the price of the computer.
Repeat part b for (g º f)(x).
Answer provided by our tutors
regular price of a computer is x dollars. Let F(x) = x-400 and g(x) = 0.75x
a.) Describe what the functions f and g model in terms of the price of the computer.
F models a discount of 400 on the price of the computer.
g models a discount of 25% on the cost of the computer
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b.) Find (f o g) (x) and describe what this models in terms of the price of the computer.
fog(x) = f[g(x)] = f[0.75x] = 0.75x-400
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Models a discount of 25% followed by a discount of 400 dollars.
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c.) Repeat part (b) for (g degree f) (x).
gof(x) = g[x-400] = 0.75(x-400)
Models a discount of 400 folled by a discount of 25%.
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d.) Which composite function models the greater discount on the computer,
fog or gof? Explain.
Compare:
gof(x) R fog(x)
0.75(x-400) R 0.75x-400
0.75x-300 R 0.75x-400
gof(x) > fog(x)
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So, fog(x) is the better discount
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e.) Find f-1 and describe what this models in terms of the price of the computer
f(x) = x-400
Interchange x and y:
x = y-400
solve for "y":
y = x+400
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The price of the computer is raised 400
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