Answer:
13/20 of a mile
Step-by-step explanation:
2/5 = 8/20
1/4 = 5/20
8/20 + 5/20 = 13/20
Answer: 125.80 ft
Step-by-step explanation:
Asuming the described situation is as shown in the figure below, we need to find the distance
between the kite and Jacks house, but first we need to find the
,
and then
.
How?
We will use trigonometry, especifically the trigonometric functions sine and cosine:
For
:
(1)
Where
is the opposite side to the angle and
the hypotenuse.
Isolating
:
(2)
For
:
(3)
Where
is the adjacent side to the angle.
Isolating
:
(4)
Finding
:
(5)

(6)
Now that we have found these values, we have to work with a bigger triangle, where the hypotenuse is the distance between the kite and Jack's house
and the sides are the values calculated in (4) and (6).
So, in this case we will use the <u>Pithagorean theorem</u>:
(7)
Isolating
and writing with the known values:
(8)
(9)
This is the distance between the kite and the house
Always try putting x=1 and x=-1 to see if we can find a zero.
If x=1 we get 5+8+1-2 which is not zero.
If we change the signs of the odd powers of x we get -5+8-1-2 which is zero so x=-1 is a zero and x+1 must therefore be a factor. Now we can use synthetic division to find the quadratic:
-1 | 5 8 1 -2
5 -5 -3 2
————
5 3 -2 | 0 = 5x²+3x-2 = (5x-2)(x+1).
Therefore the real zeroes are -1, 2/5, since -1 is a duplicate zero (because the cubic factorises into (5x-2)(x+1)²).