Function Intercepts Transformations D4D903
1. **Problem statement:** Given the graph of $f$ with x-intercept $(5,0)$ and y-intercept $(0,8)$, find:
(a) The y-intercept of $f(x) + 3$.
(b) The y-intercept of $f(4x)$.
(c) The x-intercept of $f(2x)$.
(d) Describe the transformation $f(x + 1)$.
2. **Recall intercept definitions:**
- The y-intercept is the value of the function at $x=0$, i.e., $f(0)$.
- The x-intercept is the value of $x$ where $f(x) = 0$.
3. **Given:**
- $f(0) = 8$ (y-intercept)
- $f(5) = 0$ (x-intercept)
4. **(a) Find y-intercept of $f(x) + 3$:**
- Evaluate at $x=0$: $f(0) + 3 = 8 + 3 = 11$
- So, y-intercept is $(0, 11)$.
5. **(b) Find y-intercept of $f(4x)$:**
- Evaluate at $x=0$: $f(4 imes 0) = f(0) = 8$
- So, y-intercept is $(0, 8)$.
6. **(c) Find x-intercept of $f(2x)$:**
- We want $f(2x) = 0$.
- Since $f(5) = 0$, set $2x = 5
ightarrow x = \frac{5}{2} = 2.5$
- So, x-intercept is $(2.5, 0)$.
7. **(d) Describe transformation $f(x + 1)$:**
- Replacing $x$ by $x + 1$ shifts the graph **left by 1 unit**.
**Final answers:**
- (a) y-intercept of $f(x) + 3$ is $(0, 11)$.
- (b) y-intercept of $f(4x)$ is $(0, 8)$.
- (c) x-intercept of $f(2x)$ is $(2.5, 0)$.
- (d) $f(x + 1)$ is the graph of $f$ shifted left by 1 unit.