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:
DG = 30
Step-by-step explanation:
Given:
DH = 6
DE = 4
EF = 16
Required:
DG
Solution:
DG = DH + HG
DG = 6 + HG
Let's find HG
Given that HE is parallel to the third side of ∆DGF, based on the side-splitter theorem, the other two sides of ∆DGF are divided proportionally.
Therefore,
DH/HG = DE/EF
6/HG = 4/16
Cross multiply
HG*4 = 16*6
HG = 96/4
HG = 24
✔️DG = 6 + HG
DG = 6 + 24
DG = 30
Answer:
The answer to the question provided is 10.