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:
Z = (60 - x + y + z) / √a + b + c
Step-by-step explanation:
Since it is a normal distribution, we must calculate the mean and standard deviation, since we do not have data, what we will do is leave them based on these:
Thus Total Mean time = M1 + M2 + M3
given:
M1 = x
M2 = y
M3 = z
Total Mean Time M = x + y + z
Now to calculate the standard deviation we first calculate the variance.
The total Variance V = V1 + V2 + V3
Given:
V1 = a
V2 = b
V3 = c
V = a + b + c
Thus Standard deviation SD of the complete operation is
SD = √ V
SD = √a + b + c
we need to find the probability that the mean time is less than or equal to 60 minutes, the first thing is to find the value of Z.
Formula of Z is:
Z = (X - M) / SD
In this case X = 60.
On plugging the values we get
Z = (60 - x + y + z) / √a + b + c
refer to the Z table and find the Probability of Z ≤ (60 - x + y + z) / √a + b + c
Answer:
x=2.2
y=-3.4
Step-by-step explanation:
subtract the second from the first
-5x=-11
x=2=2
substituting by x in the first equation
so y=-3.4
Answer:
easy the answer is d)y=2
Step-by-step explanation:
why because
3y−4=6−2y
Add 2y to both sides.
3y−4+2y=−2y+6+2y
5y−4=6
Add 4 to both sides.
5y−4+4=6+4
5y=10
Divide both sides by 5.
5y/5 = 10/5
y=2
11/20 = 55%
hope this helps