To analyze the quadratic equation \( y = x^2 - 8x + 15 \), we will identify the key points: the vertex, x-intercepts, and y-intercept.
1. X-Intercepts
The x-intercepts occur where \( y = 0 \):
\[
0 = x^2 - 8x + 15.
\]
Factoring the quadratic, we look for two numbers that multiply to \( 15 \) and add to \( -8 \). These numbers are \( -3 \) and \( -5 \):
\[
0 = (x - 3)(x - 5).
\]
Setting each factor to zero gives:
\[
x - 3 = 0 \quad \Rightarrow \quad x = 3,
\]
\[
x - 5 = 0 \quad \Rightarrow \quad x = 5.
\]
Thus, the x-intercepts are \( (3, 0) \) and \( (5, 0) \).
2. Y-Intercept
The y-intercept occurs where \( x = 0 \):
\[
y = 0^2 - 8(0) + 15 = 15.
\]
Thus, the y-intercept is \( (0, 15) \).
3. Vertex
The vertex of a quadratic \( y = ax^2 + bx + c \) can be found using the formula for the x-coordinate of the vertex:
\[
x = -\frac{b}{2a}.
\]
Here, \( a = 1 \) and \( b = -8 \):
\[
x = -\frac{-8}{2 \cdot 1} = \frac{8}{2} = 4.
\]
Now, substituting \( x = 4 \) back into the equation to find the y-coordinate of the vertex:
\[
y = (4)^2 - 8(4) + 15 = 16 - 32 + 15 = -1.
\]
Thus, the vertex is \( (4, -1) \).
Summary of Key Points
- X-Intercepts: \( (3, 0) \) and \( (5, 0) \)
- Y-Intercept: \( (0, 15) \)
- Vertex: \( (4, -1) \)
Final Response
- x-intercepts: \( (3, 0) \) and \( (5, 0) \)
- y-intercept: \( (0, 15) \)
- vertex: \( (4, -1) \)