1)well if there's a eqation like -3xsquared-9x+1 , then how will you find the vertex.
2)and if you have that exact same equation and you have to write it in this form: a(x-h)squared+ k , how will you do that.
thanks!!
2006-12-04 13:59:41 · 3 answers · asked by tweety_mm19 2 in Science & Mathematics ➔ Mathematics
You'll need to use the quadratic formula to find the two roots.
The roots are (h,k). The vertex x value lies halfway between the two roots, plug in the vertex x value to find the y value.
9+/- 4sqrt6
--------------- are the two roots.
6
2006-12-04 14:04:06 · answer #1 · answered by davidosterberg1 6 · 0⤊ 0⤋
If by vertex you mean a maximum or minimum, that's the point where the slope or derivative = 0.
1) The derivative of -3*x^2 - 9*x + 1 is -6*x - 9. So the minimum is at x=-1.5.
2) a*(x-h)^2 + k = a*(x^2-2*h*x+h^2) + k. The derivative is 2*a*x - 2*a*h = 2*a*(x-h). The constant terms disappear, the x disappears from terms with x to the 1st power, and in terms with x^2, x replaces x^2 and the coefficient is multiplied by 2. The rule of differentiation of terms containing powers of x is d/dx(a*x^n) = n*a*x^(n-1).
2006-12-04 14:14:16 · answer #2 · answered by kirchwey 7 · 0⤊ 0⤋
well for 1 -3xsquared is 9x
so 9x-9x=0 that plus 1 is 1 thats how to solve number 1
2006-12-04 14:02:59 · answer #3 · answered by Anonymous · 0⤊ 0⤋