Answer:
4.2 cm
Step-by-step explanation:
The law of cosines is applicable.
l² = k² +m² -2km·cos(L)
l² = 5.1² +1.2² -2·5.1·1.2·cos(35°) ≈ 17.4236
l ≈ √17.4236
l ≈ 4.2 . . . cm
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
Answer:
Step-by-step explanation:
<u><em>Given Equation is </em></u>
=> 
Comparing it with 
, we get
=> a = 2, b = 7 and c = -9
So,
Sum of roots = α+β = 
α+β = -7/2
Product of roots = αβ = c/a
αβ = -9/2
<em>Now, Finding the equation whose roots are:</em>
α/β ,β/α
Sum of Roots = 
Sum of Roots = 
Sum of Roots = 
Sum of roots = 
Sum of roots = 
Sum of Roots = 
Sum of roots = 
Sum of roots = S = 
Product of Roots = 
Product of Roots = P = 1
<u><em>The Quadratic Equation is:</em></u>
=> 
=> 
=> 
=>
This is the required quadratic equation.
D. 5x = 45 because you are trying to find x, the number of tickets that must be sold to earn $45.
