HELP ASAP! please need answer fast
2 answers:
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Answer:
-2, 8/3
Step-by-step explanation:
You can consider the area to be that of a trapezoid with parallel bases f(a) and f(4), and width (4-a). The area of that trapezoid is ...
A = (1/2)(f(a) +f(4))(4 -a)
= (1/2)((3a -1) +(3·4 -1))(4 -a)
= (1/2)(3a +10)(4 -a)
We want this area to be 12, so we can substitute that value for A and solve for "a".
12 = (1/2)(3a +10)(4 -a)
24 = (3a +10)(4 -a) = -3a² +2a +40
3a² -2a -16 = 0 . . . . . . subtract the right side
(3a -8)(a +2) = 0 . . . . . factor
Values of "a" that make these factors zero are ...
a = 8/3, a = -2
The values of "a" that make the area under the curve equal to 12 are -2 and 8/3.
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<em>Alternate solution</em>
The attachment shows a solution using the numerical integration function of a graphing calculator. The area under the curve of function f(x) on the interval [a, 4] is the integral of f(x) on that interval. Perhaps confusingly, we have called that area f(a). As we have seen above, the area is a quadratic function of "a". I find it convenient to use a calculator's functions to solve problems like this where possible.
Answer:
Step-by-step explanation:
Given the following :
Laps - - - - - - - - 5 - - - 6 - - - 7 - - - 8 - - - 9
Total time - - - 25 - - 28 - - 29 - - 30 - - 32
Using online graphing tool:
The y - axis named dependent variable represents the total time taken.
The x-axis, represents the number of laps.
The equation of the trend line attached to the plot is in the form :
y = mx + c
y = 1.6x + 17.6
Where y = total time taken
x = number of laps
m = 1.6 = gradient of the line (change in y / change in x)
C = 17.6 = intercept (whee the trndline intersects the y-axis).
