25/64 is the answer to your question
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.
We know that the building must form a right angle with the ground, so the triangle formed by the ladder, the wall, and the distance between the base of the ladder and the wall is a right triangle. We can use the Pythagorean theorem to find the distance the ladder is from the building.
a^2 + b^2 = c^2
We know that the ladder is the hypotenuse because it is opposite the right angle.
a^2 + b^2 = 20^2
Substitute the length of the other side and solve.
a^2 + 17^2 = 20^2
a^2 + 289 = 400
a^2 = 111
The distance from the wall to the bottom of the ladder is the square root of 111 or approximately 10.5357 feet
Answer:
(1,3) should be the answer due to the fact that both lines intersect at that point.
Step-by-step explanation: