While visiting a memorial, a person approximated the angle of elevation to the top of the memorial to be 35º. After walking 255
ft closer, he guessed that the angle of elevation had increased by 17º. Approximate the height of the memorial, to the top of the memorial.
1 answer:
Draw a diagram to illustrate the problem as shown in the figure below.
Let h the height of the hill. =
At position A, the angle of elevation is 40°, and the horizontal distance to the foot of the hill is x.
By definition,
tan(40°) = h/x h = x tan40 = 0.8391x
(1)
At position B, Joe is (x - 450) ft from the foot of the hill. His angle of elevation is
40 + 18 = 58°.
By definition, tan(58°) = h/(x - 450)
h = (x - 450) tan(58°) = 1.6003(x-450)
h = 1.6003x - 720.135 (2)
Equate (1) and (2).
1.6003x - 720.135 = 0.8391x 0.7612x = 720.135
x = 946.0523
From (1), obtain
h = 0.8391*946.0523 = 793.8 ft
Answer: The height of the hill is approximately 794 ft (nearest integer)
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Answer:
The minimum possible initial amount of fish:
Step-by-step explanation:
Let's start by saying that
= is the initial number of fishes
John:
When John arrives:
- he throws away one fish from the bunch
- divides the remaining fish into three.
- takes a third for himself.
the remaining fish are expressed by the above expression. Let's call it John
and simplify it!
When Joe arrives:
- he throws away one fish from the remaining bunch
- divides the remaining fish into three
- takes a third for himself.
the remaining fish are expressed by the above expression. Let's call it Joe
and simiplify it
since we've already expressed John in terms of x, we express the above expression in terms of x as well.
When James arrives:
We're gonna do this one quickly, since its the same process all over again
This is the last remaining pile of fish.
We know that no fish was divided, so the remaining number cannot be a decimal number. <u>We also know that this last pile was a multiple of 3 before a third was taken away by James</u>.
Whatever the last remaining pile was (let's say ), a third is taken away by James. the remaining bunch would be
hence we've expressed the last pile in terms of n as well. Since the above 'James' equation and this 'n' equation represent the same thing, we can equate them:
L.H.S must be a Whole Number value and this can be found through trial and error. (Just check at which value of n does 2n/3 give a non-decimal value) (We've also established from before that n is a multiple a of 3, so only use values that are in the table of 3, e.g 3,6,9,12,..
at n = 21, we'll see that 2n/3 is a whole number = 14. (and since this is the value of n to give a whole number answer of 2n/3 we can safely say this is the least possible amount remaining in the pile)
by solving this equation we'll have the value of x, which as we established at the start is the number of initial amount of fish!
This is minimum possible amount of fish before John threw out the first fish