Questions: Evaluate the piecewise-defined function.
f(x)=
4x if x<0
7-x if 0 ≤ x<4
x if x ≥ 4
(a) f(-0.5)=
(b) f(0)=
(c) f(4)=
Transcript text: Evaluate the piecewise-defined function.
\[
f(x)=\left\{\begin{array}{ll}
4 x & \text { if } x<0 \\
7-x & \text { if } 0 \leq x<4 \\
|x| & \text { if } x \geq 4
\end{array}\right.
\]
(a) $f(-0.5)=$ $\square$
(b) $f(0)=$ $\square$
(c) $f(4)=$ $\square$
Solution
Solution Steps
To evaluate the piecewise-defined function \( f(x) \) at specific points, we need to determine which condition each point satisfies and then apply the corresponding function rule.
(a) For \( f(-0.5) \), since \( -0.5 < 0 \), we use the rule \( f(x) = 4x \).
(b) For \( f(0) \), since \( 0 \leq x < 4 \), we use the rule \( f(x) = 7 - x \).
(c) For \( f(4) \), since \( x \geq 4 \), we use the rule \( f(x) = |x| \).
Step 1: Evaluate \( f(-0.5) \)
For \( f(-0.5) \), since \( -0.5 < 0 \), we use the rule \( f(x) = 4x \):
\[
f(-0.5) = 4 \times (-0.5) = -2.0
\]
Step 2: Evaluate \( f(0) \)
For \( f(0) \), since \( 0 \leq x < 4 \), we use the rule \( f(x) = 7 - x \):
\[
f(0) = 7 - 0 = 7
\]
Step 3: Evaluate \( f(4) \)
For \( f(4) \), since \( x \geq 4 \), we use the rule \( f(x) = |x| \):
\[
f(4) = |4| = 4
\]