Solution
Let's solve the given problems step by step.
Given functions:
- f(x)=2x−4
- g(x)=6−x
We need to evaluate these functions at specified points or perform operations involving these functions.
(a) (f+g)(2)
To find (f+g)(2), we add f(2) and g(2):
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Calculate f(2):
f(2)=2(2)−4=4−4=0
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Calculate g(2):
g(2)=6−2=4
-
Therefore,
(f+g)(2)=f(2)+g(2)=0+4=4
(b) (f−g)(−6)
To find (f−g)(−6), we subtract g(−6) from f(−6):
-
Calculate f(−6):
f(−6)=2(−6)−4=−12−4=−16
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Calculate g(−6):
g(−6)=6−(−6)=6+6=12
-
Therefore,
(f−g)(−6)=f(−6)−g(−6)=−16−12=−28
(c) (g−f)(1)
To find (g−f)(1), we subtract f(1) from g(1):
-
Calculate g(1):
g(1)=6−1=5
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Calculate f(1):
f(1)=2(1)−4=2−4=−2
-
Therefore,
(g−f)(1)=g(1)−f(1)=5−(−2)=5+2=7
(d) (g⋅f)(21)
To find (g⋅f)(21), we multiply g(21) by f(21):
-
Calculate g(21):
g(21)=6−21=212−21=211
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Calculate f(21):
f(21)=2(21)−4=1−4=−3
-
Therefore,
(g⋅f)(21)=g(21)⋅f(21)=211⋅(−3)=−233
(e) (gf)(−4)
To find (gf)(−4), we divide f(−4) by g(−4):
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Calculate f(−4):
f(−4)=2(−4)−4=−8−4=−12
-
Calculate g(−4):
g(−4)=6−(−4)=6+4=10
-
Therefore,
(gf)(−4)=g(−4)f(−4)=10−12=−56
(f) (fg)(−3)
To find (fg)(−3), we divide g(−3) by f(−3):
-
Calculate g(−3):
g(−3)=6−(−3)=6+3=9
-
Calculate f(−3):
f(−3)=2(−3)−4=−6−4=−10
-
Therefore,
(fg)(−3)=f(−3)g(−3)=−109=−109
Final Results:
- (a) (f+g)(2)=4
- (b) (f−g)(−6)=−28
- (c) (g−f)(1)=7
- (d) (g⋅f)(21)=−233
- (e) (gf)(−4)=−56
- (f) (fg)(−3)=−109
Would you like further details or have any questions?
Follow-up Questions:
- What is the process for finding the sum of two functions?
- How do you evaluate a function at a specific point?
- What does it mean to find the difference between two functions?
- How is multiplication between two functions performed?
- What steps are involved in dividing one function by another?
Tip:
Always carefully substitute values into functions and simplify step-by-step to avoid calculation errors.