9514 1404 393
Answer:
78.5 km
Step-by-step explanation:
Measured at the airport, the angle between the two planes is ...
180° -60° -50° = 70°
The law of cosines tells us the distance between the planes is ...
d = √(50² +80² -2·50·80·cos(70°)) ≈ √6163.84 ≈ 78.5 . . . km
The planes are about 78.5 km apart.
Answer:
A
Step-by-step explanation:
Recall the general equation for a straight line is
y = mx + b
where m is the gradient and b is the y-intercept
given 2 points whose coordinates are (x1, y1) and (x2, y2), m can be found with the following formula:
m =
in this case, x1 = -8, y1 = 11, x2 = 4, y2=7/2
applying these values to the formula for m will give
m = -(5/8)
We can see immediately that the only 2 possible answers are A or B.
If we substitute this back into the general equation, we get:
y = -(5/8)x + b
In order to find the value for b, we substitute any one of the 2 given points back into this equation. Lets choose (-8,11)
11 = -(5/8) (-8) + b
11 = -(5/8) (-8) + b
11 = 5 + b
b = 6
hence A is the answer.