what would the vertex be of this equation:
y=x^2 + 4x + 3. my teacher showed us two ways to do it and i got two different answers. the answers i got were (-4,3) and (-2,-1) which one is correct? thanks in advance for your help.
2006-06-23 15:11:53 · 7 answers · asked by krystal 6 in Education & Reference ➔ Homework Help
i dont have a graphing calculator!
2006-06-23 15:18:36 · update #1
i just need to know the vertex, using the quadratic formula or factoring wont get me the answer i need.
2006-06-23 15:20:06 · update #2
(-2,-1) is the vertex in this problem, using the equation (-b/2a), then plugging the answer for a back into the original equation as x to find y. so whatever you did to get (-2,-1) that is the way to do it. Also parabola will be facing up and will cross the y axis at +3 (find this by setting x=0). Hope it helps you.
2006-06-23 15:25:02 · answer #1 · answered by missyboo_79 4 · 0⤊ 0⤋
First solve for the x-intercepts:
y = (x+3)(x+1) = 0
x = -3 or -1
The number halfway between -3 and -1 indicates the x value of the vertex: [-3 + (-1)] / 2 = -2
Now, plug x = -2 into the original equation:
y = (-2)^2 + 4(-2) +3 = -1
The point of the vertex is then (-2, -1)
x- intercepts: (-3,0) and (-1,0)
Plot those three points and connect the dots.
2006-06-23 22:20:06 · answer #2 · answered by Anonymous · 0⤊ 0⤋
(-2,-1) is the vertex. (-4,3) is just another point on the curve.
2006-06-23 22:39:38 · answer #3 · answered by el torpedo 2 · 0⤊ 0⤋
(-2,-1).
2006-06-23 22:19:37 · answer #4 · answered by bendoes 2 · 0⤊ 0⤋
either do the quadratic formula (remember order of operations) or factor
2006-06-23 22:18:13 · answer #5 · answered by april9922 3 · 0⤊ 0⤋
pi
2006-06-23 22:18:40 · answer #6 · answered by The Sniper M 1 · 0⤊ 0⤋
just use a graphing calculator DUH
2006-06-23 22:15:58 · answer #7 · answered by jms_nov28 3 · 1⤊ 0⤋