Answer:
This tells us that the vertex is at (−2, 9) and the equation of the axis of symmetry is x = −2. To find the x-intercepts, we put y = 0 to obtain
(x + 2)2 − 9 = 0
(x + 2)2 = 9
x + 2 = 3 or x + 2 = −3
x = 1 or x = −5.
Explanation:
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The standard form of a quadratic equation is written as y=ax2+bx+c, where x and y are variables and a, b, and c are known constants. To find the y-intercept from a quadratic equation, substitute 0 as the value for x and solve. The y-intercept is always equal to the value of c in the equation.