SOLUTION: f={(1,2),(2.3),(3,4)},g={(2,3),(3,2),(4,8)} a) Find (f*g)(x)= b) Find (g*f)(x)=

SOLUTION: f={(1,2),(2.3),(3,4)},g={(2,3),(3,2),(4,8)} a) Find (fg)(x)= b) Find (gf)(x)=

Question 1128484: f={(1,2),(2.3),(3,4)},g={(2,3),(3,2),(4,8)}
a) Find (f*g)(x)=
b) Find (g*f)(x)=
Answer by greenestamps(13334) (Show Source): You can put this solution on YOUR website!

I will assume this question came from the same person whose similar question I just answered....

Again, "(f*g)(x)" is simply f(x)*g(x); "(g*f)(x)" is simply g(x)*f(x). So the answers to the two questions would be the same.

So again I assume you mean f(g(x)) and g(f(x)).

a) f(g(x)) can only exist for input values for which g(x) is defined: 2, 3, and 4.

f(g(2)) = f(3) = 4 --> (2,4)
f(g(3)) = f(2) = 3 --> (3,3)
f(g(4)) = f(8) but f(8) is not defined

So f(g(x)) = {(2,4), (3,3)}

b) g(f(x)) can only exist for input values for which f(x) is defined: 1, 2, and 3.

g(f(1)) = g(2) = 3 --> (1,3)
g(f(2)) = g(3) = 2 --> (2,2)
g(f(3)) = g(4) = 8 --> (3,8)

So g(f(x)) = {(1,3), (2,2), (3,8)}
RELATED QUESTIONS
Given f(x)=x/(x-1) , g(x)=(2x-4)/x find the following a) (f�g)(0) b) (g�f)(-2)... (answered by stanbon)

If f(x)=2x-1 and g(x)=x^2 find : 1. g(g(x)) 2. g(f(x)) 3. f(g(x)) 4.... (answered by fcabanski)

suppose f(x)=3x-4 and g(x)=x+3.. find each value.. 6. f(2) 7.f(1/3)+g(-2)... (answered by Mathtut)

Find (g � f)(4) for the functions below: F(x)=x+3, g(x) = 1/x^2 (g � f)(4) = (answered by Alan3354)

3. If f(x)=square root 2x^2-1 and g(x)=x^1/2, find (and simplify) a) (f+g)(x) b)... (answered by CPhill)

x | 0 | 1 | 2 | 3 | 4 f(x) | 3 | 4 | 0 | 2 | 1 g(x) | 2 | 1 | 3 | 4 | 0 Find... (answered by only4christ2)

Given f(x)=2x+3 and g(x)=x^2-3x+4 find following: 1. f(3) 2. g(-2) 3. f(b) 4.... (answered by solver91311)

if f(x)=2x+4 and g(x)=x^2+1, find (f o... (answered by Nate)

Suppose F(x) = f(g(x)) where f(-2)=8 f'(-2)=4 f'(5)=3 g(5)=-2 g'(5)=6 Find... (answered by math_tutor2020)

f(x) = 7/x g(x) = 9/x+9 Find: 1. (f + g)(x) 2. (f − g)(x) 3. (fg)(x) 4.... (answered by josgarithmetic)