Identify the vertex for the graph of y = 3x2 + 12x + 5.
Solution
The given equation is a quadratic equation of the form ax2 + bx + c.
Therefore a = 3; b = 12 and c = 5.
Since a is +ve the parabola represented by this equation is opening upwards and the x - coordinate of its vertex is given by the expression
x = -b/2a
x = -12/2(3) = -2
The y- coordinate of the vertex can be obtained by substituting the value of x in the given quadratic equation :
y = 3x2 + 12x + 5
= 3(-2)2 + 12(-2) + 5
= 3(4) - 24 + 5
= 12 - 24 + 5
= -7
The vertex of the graph of the equation is given by coordinates of (-2, -7)
Identify the vertex for the graph of y = 3x2 + 12x + 5.
Summary:
The vertex for the graph of y = 3x2 + 12x + 5 is the point with coordinates (-2, -7).
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