A parabola is a quadratic function, and a quadratic can be expressed in vertex form, which is:
y=a(x-h)^2+k, where (h,k) is the vertex (absolute maximum or minimum point of the quadratic)
In this case we are given that (h,k) is (-5,80) so we have so far:
y=a(x--5)^2+80
y=a(x+5)^2+80, we are also told that it passes through the point (0,-45) so:
-45=a(0+5)^2+80
-45=25a+80 subtract 80 from both sides
-125=25a divide both sides by 25
-5=a, so now we know the complete vertex form is:
y=-5(x+5)^2+80
The x-intercepts occur when y=0 so:
0=-5(x+5)^2+80 add 5(x+5)^2 to both sides
5(x+5)^2=80 divide both sides by 5
(x+5)^2=16 take the square root of both sides
x+5=±√16 which is
x+5=±4 subtract 5 from both sides
x=-5±4 so the x-intercepts are:
x=-1 and -9
Answer:
A. 4^-2•3 .............................
Answer:
588 english tst ok alright
Answer: 109 years old
Step-by-step explanation:
2009-1900=109
Answer:
x = 28
m∠ACD = 68°
Step-by-step explanation:
∠BAE ≅∠DAC because they are vertical angles
∠ACD = 180 - 124 = 56°
to find 'x': 56 + 2x + (180 - 4x) = 180
236 - 2x = 180
-2x = -56
x = 28
m∠ACD = 180 - 4(28) = 180 - 112 = 68°
