Questions: If f(x) is a linear function, f(-4)=-5, and f(4)=4, find an equation for f(x)
f(x)=
Transcript text: If $f(x)$ is a linear function, $f(-4)=-5$, and $f(4)=4$, find an equation for $f(x)$
\[
f(x)=
\]
Solution
Find the equation of the linear function \( f(x) \) given \( f(-4) = -5 \) and \( f(4) = 4 \).
Step 1: Determine the slope of the linear function.
The slope \( m \) of a linear function passing through two points \( (x_1, y_1) \) and \( (x_2, y_2) \) is given by:
\[
m = \frac{y_2 - y_1}{x_2 - x_1}
\]
Substitute the given points \( (-4, -5) \) and \( (4, 4) \):
\[
m = \frac{4 - (-5)}{4 - (-4)} = \frac{9}{8}
\]
Step 2: Use the point-slope form to find the equation of the line.
The point-slope form of a linear equation is:
\[
y - y_1 = m(x - x_1)
\]
Using the slope \( m = \frac{9}{8} \) and the point \( (4, 4) \):
\[
y - 4 = \frac{9}{8}(x - 4)
\]
Simplify the equation:
\[
y = \frac{9}{8}x - \frac{9}{8} \cdot 4 + 4
\]
\[
y = \frac{9}{8}x - \frac{36}{8} + 4
\]
\[
y = \frac{9}{8}x - \frac{9}{2} + 4
\]
\[
y = \frac{9}{8}x - \frac{1}{2}
\]
The equation of the linear function is:
\[
\boxed{f(x) = \frac{9}{8}x - \frac{1}{2}}
\]
The equation of the linear function is:
\[
\boxed{f(x) = \frac{9}{8}x - \frac{1}{2}}
\]