Function Notation Notes

Function Notation Notes

Write in function notation:

y=x^2+x

y=8x-5

f(x)=x^2+x

g(x)=8x-5

Find f(4)

f(4)=(4)^2+4
f(4)=16+4
f(4)=20

Find g(4)

g(4)=8(4)-5
g(4)=32-5
g(4)=27

f(x-3)=(x-3)^2+x-3
f(x-3)=(x-3)(x-3)+x-3
f(x-3)=x^2-3x-3x+9+x-3
f(x-3)=x^2-5x+6

Idea: Plug in a number and replace x with that value

Summary: In function notation, y turns into f(x).  x is the input and f(x) is the output.  You plug x into the equation to evaluate it.

Source: YouTube-- Function Notation (by PatrickJMT)
Picture from:
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In a graph, x=the input values and f(x)= the output values