Answer:
Given quadratic equation: y = (x - 3)(x + 3)
Zeros (x-intercepts)
The zeros of a quadratic equation are the points where the graph of the quadratic equation crosses the x-axis. So the x-intercepts (zeros) are when y = 0
⇒ (x - 3)(x + 3) = 0
⇒ (x - 3) = 0 so x = 3
⇒ (x + 3) = 0 so x = -3
Therefore, the x-intercepts are at (3, 0) and (-3, 0).
y-intercept
The y-intercept is the point where the graph crosses the y-axis. So the y-intercept is when x = 0
⇒ (0 - 3)(0 + 3) = -9
Therefore, the y-intercept is at (0, -9)
Vertex
Expand the equation so that it is in standard form y = ax² + bx + c:
⇒ y = x² - 9
x-value of vertex is -b / 2a ⇒ -0 / 2 = 0
substitute the found value of x into the equation to find y:
⇒ y = (0)² - 9 = -9
Therefore, the vertex is (0, -9)
Axis of symmetry
Axis symmetry of a quadratic equation is x = a where a is the x-value of the vertex.
Therefore, the axis of symmetry is x = 0