Section 4.3: Evaluating Functions
Evaluating a function means finding the output value for a given input using the function rule.
Example 1
Given \( f(x) = 2x + 3 \), find \( f(4) \) and \( f(-2) \).
\( f(4) = 2(4) + 3 = 11 \)
\( f(-2) = 2(-2) + 3 = -1 \)
Example 2
For \( g(x) = x^2 - 5x + 6 \), evaluate \( g(1) \) and \( g(3) \).
\( g(1) = 1 - 5 + 6 = 2 \)
\( g(3) = 9 - 15 + 6 = 0 \)
Practice Problems
- Evaluate \( f(x) = 3x - 4 \) for \( x = 0, 2, -1 \).
- Evaluate \( h(x) = x^2 + 2x + 1 \) for \( x = -1, 0, 3 \).
- Evaluate \( k(x) = 5 - 2x \) for \( x = 2, -3 \).
- Evaluate \( p(x) = x^3 - x \) for \( x = 1, -2 \).
- Given \( m(x) = 4x + 7 \), find \( m(-1) \) and \( m(5) \).