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Combinations of Functions. Objective. To be able to perform operations and combinations of functions algebraically, graphically, and with the use of technology. Relevance. To be able to model a set of raw data after a function to best represent that data.
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Objective • To be able to perform operations and combinations of functions algebraically, graphically, and with the use of technology.
Relevance • To be able to model a set of raw data after a function to best represent that data.
Operations with Functions: • Sum • Difference • Product • Quotient
Find f + g Find f - g Example: Let f(x) = 5x² -2x +3 and g(x) = 4x² +7x -5
Using your GDC Start with “VARS”
Find f · g Find f/g Example: Let f(x) = 5x² and and g(x) = 3x – 1.
Find: + 4 = 5 1
Find: = - 4 0 + - 4
Find: 0 - 4 = - 4
Find: 3 - (- 4) = 7
Find: 5 x 4 = 20
Find: - 3 x 5 = - 15
Find: 6 3 = 2
A composite function is a combination of two functions. • You apply one function to the result of another.
The composition of the function f with the function g is written as f(g(x)), which is read as ‘f of g of x.’ • It is also known as which is read as ‘f composed with g of x.” • In other words:
Ex: f(x)=2x + 5 and g(x) = x - 3 • You can work out a single “rule” for the composite function in terms of x.
Do you think will give you the same result? NO!
You Try…. f(x) = 2x + 2 g(x) = (x + 2)2 Find:
You may need to evaluate a composite function for a particular value of x. Method 1: Work out the composite function. Then substitute 3 for x.
You may need to evaluate a composite function for a particular value of x. Method 2: Substitute 3 into g(x). Substitute that value into f(x).