Answer: the sale price is $2.70
Step-by-step explanation:
Discount = Original Price x Discount %/100
Discount = 18 × 85/100
Discount = 18 x 0.85
You save = $15.30
Final Price = Original Price - Discount
Final Price = 18 - 15.3
Final Price = $2.70
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:
The domain of function 
is set of all real numbers.
Domain: (-∞,∞)
Step-by-step explanation:
Given:
the domain of both the above functions is all real number.
To find domain of :
Substituting functions 
and 
to find
The product can be written as difference of squares. ![[a^2-b^2=(a+b)(a-b)]](https://tex.z-dn.net/?f=%5Ba%5E2-b%5E2%3D%28a%2Bb%29%28a-b%29%5D)
∴ 
The degree of the function is 2 as the exponent of leading term 
is 2. Thus its a quadratic equation.
For any quadratic equation the domain is set of all real numbers.
So Domain of is (-∞,∞)
