Posted by T.Gracken on October 24, 2002 at 14:16:27:
In Reply to: parabolas posted by joyce on October 24, 2002 at 13:53:44:
: here is an example problem of the work i need help on... y = f(x) = -3x squared + 24x -44 how do you find the vertex in the form (x,y)??? how do you find the x axis intercept?
if you have an equation in the form y =Ax2 + Bx + C (A, B, and C real numbers and A not equal 0), then the x-coordinate of the vertex can be found by evaluating [-B/(2A)]
so, for your equation, the x-coordinate of the vertex is [-24/(2*(-3))] = 4.
to determine the y-coordinate of the vertex, substitute the x-coordinate into the original equation.
As to the x-intercepts, substitute 0 in place of y and solve the resulting equation for x. (there may be none, one, or two real number answers)
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