Idk i need the points and how is this for math
Answer:
C(5,3)=10
Pictures 1,2,3,4,5
So the Possible sets are:
(1,2,3) (1,2,4)
(1,2,5) (1,3,4)
(1,3,5) (1,4,5)
(2,3,4) (2,3,5)
(2,4,5) (3,4,5)
The question is find the height of the tree, given that at two points 65 feet apart on the same side of the tree and in line with it, the angles of elevaton of the top of the tree are 21° 19' and 16°20'.
1) Convert the angles to decimal form:
19' * 1°/60' = 0.32° => 21° 19' = 21.32°
20' * 1°/60' = 0.33° => 16° 20' = 16.33°
2) Deduce the trigonometric ratios from the verbal information.
You can form a triangle with
- horizontal leg x + 65 feet
- elevation angle 16.33°
- vertical leg height of the tree, h
=> trigonometric ratio: tan (16.33) = h /( x + 65) => h = (x+65) * tan(16.33)
You can form a second triangle with:
- horizontal leg x
- elevation angle 21.32°
- vertical leg height of the tree, h
=> trigonometric ratio: tan(21.32) = h / x => h = x * tan(21.32)
Now equal the two expressions for h:
(x+65)*tan(16.33) = x*tan(21.32)
=> x*tan(16.33) + 65*tan(16.33) = x*tan(21.32)
=> x*tan(21.32) - x*tan(16.33) = 65*tan(16.33)
=> x = 65*tan(16.33) / [ tan(21.32) - tan(16.33) ] = 195.73 feet
=> h = 195.73 * tan(21.32) = 76.39 feet.
Answer: 76.39 feet
Answer: the speed of the current is 0.6 mph
Step-by-step explanation:
Let x represent the speed of the current.
James is kayaking. He can row 3 mph in still water. If he can travel 6 miles downstream. Assuming he went with the current, it means that his total speed while travelling downstream is (3 + x)
Time = distance/speed
Time taken to travel downstream is
6/(3 + x)
In the same amount of time, he can travel 4 miles upstream. Assuming he went against the current, it means that his total speed while travelling downstream is (3 - x). Time taken to travel upstream is
4/(3 - x)
Since the time is the same, then
6/(3 + x) = 4/(3 - x)
Cross multiplying, it becomes
6(3 - x) = 4(3 + x)
18 - 6x = 12 + 4x
4x + 6x = 18 - 12
10x = 6
x = 6/10
x = 0.6 mph