find the x-intercept and the coordinates of the vertex for the parabola
y = x^2 + 2x - 15
If there is more than one x-intercept, than write them all
what is the x-intercepts?
What is the vertex?
2007-03-08 15:45:18 · 3 answers · asked by Tracey N 1 in Science & Mathematics ➔ Mathematics
y=o
x^2 +2x-15=0
x^2+5x-3x-15=0
x(x+5)-3(x+5)=0
x= -5 x=3---> x-intercepts
vertex:
complete the square
y=( x^2 +2x +1)-1-15
=(x+1)^2 -16
vertex:(-1,-16)
2007-03-08 15:55:09 · answer #1 · answered by Maths Rocks 4 · 0⤊ 0⤋
ah easy question
x intercept is when y = 0
x^2 + 2x - 15 = (x+5)(x-3) = 0
x = -5 or 3, those are x intercepts
vertex formula is (-b/2a, (4ac-b^2)/4a) so vertex is (-1, -16)
2007-03-08 23:58:36 · answer #2 · answered by fomalhaut 2 · 0⤊ 0⤋
Let's see... Y=mx+b, so 2x is your Y intercept. X^ is your X is your X intercept, and 2 is your slope.
2007-03-08 23:55:01 · answer #3 · answered by mtoutlaw_87 3 · 0⤊ 1⤋