hi all, can the quadratic formula be used to find the x intercepts, y intercept and the vertex of a parabola?

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- March 31st 2012, 06:47 AMdavellew69quadratic formula
hi all, can the quadratic formula be used to find the x intercepts, y intercept and the vertex of a parabola?

- March 31st 2012, 07:59 AMHallsofIvyRe: quadratic formula
Given a quadratic function of the form f(x)= ax^2+ bx+ c, you can find the y- intercept simply by setting x= 0. No "quadratic formula" required there. To find the vertex, you want to rewrite the funtion as f(x)= (x- x_0)^2+ y_0 which you can do by "completing the square". Completing the square is a standard way of getting the "quadratic formula" but that formula is not needed. To find the x- intercept, you need to solve ax^2+ bx+ c= 0. You

**can**use the quadratic formula to solve that but you could also factor or complete the square. - March 31st 2012, 08:17 AMdavellew69Re: quadratic formula
thanks