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ACT Test Prep I-2. 3 x ³ ·2 x ² y ·4 x ² y is equivalent to: F. 9 x⁷y² G. 9 x¹²y² H. 24 x⁷y² J. 24 x¹²y K. 24 x¹²y². 1.2 Composition of Functions. Operations with Functions. Sum: Difference: Product: Quotient:. Example 1:.
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ACT Test Prep I-2 3x³ ·2x²y ·4x²y is equivalent to: F. 9x⁷y² G. 9x¹²y² H. 24x⁷y² J. 24x¹²y K. 24x¹²y²
Operations with Functions • Sum: • Difference: • Product: • Quotient:
Example 1: Given f(x) = 2x – 1 and g(x) = x², find each function. • (f + g) (x) • (f - g) (x) • (f · g) (x) d.
More examples: Given f(x) = 3x² + 4x – 5 and g(x) = 2x + 9, find each function. • (f + g) (x) • (f - g) (x) • (f · g) (x) d.
For the Lotsa Coffee Shop, the revenue r(x) in dollars from selling x cups of coffee is r(x)=1.5 x. The cost c(x) for making and selling the coffee is c(x) = 0.2x + 110. • Write the profit function • Profit function = revenue – cost: p(x) = r(x) – c(x) • Find the profit on 100, 200, and 500 cups of coffee sold.
Composition of Functions The term "composition of functions" (or "composite function") refers to the combining of functions in a manner where the output from one functionbecomes the input for the next function. In math terms, the range (the y-value answers) of one function becomesthe domain (the x-values) of the next function
The notation used for composition is: (f ◦g) (x) = f (g(x)) and is read "f composed with g of x" or "f of g of x". Notice how the letters stay in the same order in each expression for the composition. f (g(x))clearly tells you to start with function g (innermost parentheses are done first).
Examples Find (f ◦ g)(x) and (g ◦ f)(x) for each f(x) and g(x). • f(x) = 2x + 5 g(x) = 3 + x • f(x) = 2x – 3 g(x)= x² - 2x 3. f(x) = x² - 2x g(x)= 3x
Domains of a Composition The domain of a composed function (f ◦ g)(x) is determined by the domains of f(x) and g(x). For example: State the domain of (f ◦ g)(x) for f(x) = g(x) =
State the domain of (f ◦ g)(x) for: • f(x) = g(x) = x + 3 • f(x) = g(x) = 7 - x
Assignment Pages 17 -18 12 – 24 even 39 Write the functions of each problem and show all work.