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Find (f+g)(3), (f-g)(3), (fg)(3), and (f/g)(3) for f(x)=x+3, g(x)=x^2

User Sharondio
by
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1 Answer

5 votes

Answer:

15, -3, 54, 2/3

Explanation:

We have:


f(x)=x+3\\g(x)=x^2


(f+g)(x) can be calculated as


(f+g)(x)=f(x)+g(x)

So in this case,


(f+g)(x)=x+3+x^2

And substituting x = 3,


(f+g)(3)=3+3+3^2=15


(f-g)(x) can be calculated as


(f-g)(x)=f(x)-g(x)

So in this case,


(f-g)(x)=x+3-x^2

And substituting x = 3,


(f+g)(3)=3+3-3^2=-3


(fg)(x) can be calculated as


(fg)(x)=f(x)g(x)

So in this case,


(fg)(x)=(x+3)(x^2)=x^3+3x^2

And substituting x = 3,


(fg)(3)=3^3+3\cdot 3^2=54


(f/g)(x) can be calculated as


(f/g)(x)=(f(x))/(g(x))

So in this case,


(f/g)(x)=(x+3)/(x^2)

And substituting x = 3,


(f/g)(3)=(3+3)/(3^2)=(2)/(3)

User Joel Falcou
by
6.7k points