Answer: f(x) = -0.016x² + 1.6x
Step-by-step explanation:
If the lenght of the road over the arch is 100m, we can consider a coordinate plane and say that the road starts at point (0,0) and finishes at (100,0). The vertice of the parabola is at point (50,40), because the maximum height is 40 and it is always in the middle point of the roots.
So, we have
(0,0) (50,40) (100,0)
A quadratic function is always on the form: f(x) = ax² + bx + c
0 = a0² + b0 + c
40 = a50² + b50 + c
0 = a100² + b100 + c
0 = a0² + b0 + c → c = 0 ∴
40 = a50² + b50
0 = a100² + b100
_________________________
2500a + 50b = 40 (*2)
10000a + 100b = 0
_________________________
5000a + 100b = 80
10000a + 100b = 0 (-)
__________________________
-5000a = 80
-a=80/5000
a=-0.016
∴
2500a + 50b = 40
2500.(-0.016) + 50b = 40
-40 + 50b = 40
50b = 80
b = 80/50
b = 1.6
This way f(x) = -0.016x² + 1.6x
When you've got a squares bracket, this simply becomes the bracket twice, therefore, (r+s)2 becomes (r+s)(r+s)
You've then go to use FOIL, and this gives you r^2+rs+sr+s^2, and this cannot be simplified any further.
Therefore, the product of this is r^2 + s^2 + rs + sr
Hope this is what you're looking for :)
Equilateral because all sides are equal
Well you will need two number that are divisible by 30 and add up to -7 so they will have to be a negative.
I would try -2 and -5 which are both divisible by 30 and ad up to -7 so...
-2/30 + -5/30 = -7/30
Answer:
21
Step-by-step explanation:
the sum of the express of the summation of the notation
