Split up the interval [0, 8] into 4 equally spaced subintervals:
[0, 2], [2, 4], [4, 6], [6, 8]
Take the right endpoints, which form the arithmetic sequence

where 1 ≤ <em>i</em> ≤ 4.
Find the values of the function at these endpoints:

The area is given approximately by the Riemann sum,

where
; so the area is approximately

where we use the formulas,


The equation is

.
We are looking for a function with a vertex above the x-axis and a function that opens upward (has coefficient a > 0).
The first function opens downward and intersects the x-axis. The second function has a vertex below the x-axis. The third function satisfies our requirements. The fourth function has a vertex on the x-axis.
We can solve this algebraically with the knowledge that the real solutions of a quadratic are its x-intercepts. If there are no x-intercepts (because it lies entirely above or below the x-axis), then there are no real solutions. This is true when the discriminant

. You can see that from the quadratic formula. This holds true for both answers A and C, so to find the correct one, we remember that when the coefficient a of the

term is positive, the graph opens upwards, so we choose
C.
Answer:
12 units
Step-by-step explanation:
Given the points :
R(−3, 2) - - - > S(2, 2) - - - - > T(2, −5).
Distance between R and S
Distance between two points is obtained thus :
D = sqrt((x2 - x1)^2 + (y2 - y1)^2)
Distance between R and S
x1 = - 3 ; y1= 2 ; x2 = 2 ; y2 = 2
D1 = sqrt((2 - (-3))^2 + (2 - 2)^2)
D1 = sqrt((5^2 + 0^2))
D1 = sqrt(25)
D1 = 5
Distance between S and T
x1 = 2 ; y1= 2 ; x2 = 2 ; y2 = - 5
D2 = sqrt((2 - 2)^2 + (-5 - 2)^2)
D2 = sqrt((0^2 + (-7)^2))
D2 = sqrt(49)
D2 = 7
Hence, total length = D1 + D2 = 5 + 7 = 12 units
answer is 525 because 775-250=525
Step-by-step explanation: