Mathematics Grade 11 15 min

Evaluate functions

Evaluate functions

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1

Introduction & Learning Objectives

Learning Objectives Evaluate polynomial, rational, and radical functions for a given numerical input. Evaluate piecewise-defined functions by selecting the correct sub-function based on the input. Evaluate logarithmic and exponential functions for specific values. Evaluate composite functions, such as f(g(x)), for a specific numerical input. Evaluate a function for an algebraic expression, such as f(a+2). Calculate and simplify the difference quotient for a given polynomial function. Interpret function notation in real-world contexts and evaluate the function for a given scenario. Ever wondered how a video game engine calculates a character's trajectory for a jump? 🎮 It's all about instantly evaluating a function that models the path! This tutorial will guide y...
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Key Concepts & Vocabulary

TermDefinitionExample FunctionA rule that assigns to each input value exactly one output value. It's like a machine that takes an input and produces a predictable output.f(x) = 2x + 3. If the input is x=4, the output is f(4) = 2(4) + 3 = 11. Input (Argument)The value that is substituted into a function. It is the independent variable, commonly denoted by 'x'.In the expression f(5), the input is 5. Output (Value)The result obtained after a function has been evaluated for a given input. It is the dependent variable, commonly denoted by 'y' or 'f(x)'.For f(x) = x^2, when the input is 3, the output f(3) is 9. DomainThe set of all possible input values (x-values) for which the function is defined.For the function f(x) = \sqrt{x}, the domain is x ≥ 0, because...
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Core Formulas

The Substitution Principle To evaluate f(a), replace every instance of the variable 'x' in the expression for f(x) with the value 'a'. This is the fundamental rule for evaluating any function. Be sure to use parentheses around the substituted value, especially if it is negative or an expression, to maintain the correct order of operations. Evaluating Composite Functions (f \circ g)(x) = f(g(x)) To evaluate a composite function, always work from the inside out. First, evaluate the inner function g(x) for the given input. Then, use the result of g(x) as the new input for the outer function f(x). The Difference Quotient D(x) = \frac{f(x+h) - f(x)}{h}, \text{ for } h \neq 0 This formula, critical for calculus, measures the average rate of change of a...

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Sample Practice Questions

Challenging
For the function f(x) = x² + 3x, find and simplify the difference quotient [f(x+h) - f(x)]/h.
A.2x + h + 3
B.2x + 3
C.h + 3
D.x² + h + 3
Challenging
Let f(x) = 1/(x-2) and g(x) = √x+5. Find the value of (f ∘ g)(11).
A.1/4
B.1/9
C.1/2
D.Undefined
Challenging
Let f(x) = 2x, g(x) = x², and h(x) = x - 1. Find the value of (f ∘ g ∘ h)(3).
A.16
B.8
C.9
D.10

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