Answer:
decreasing at 390 miles per hour
Step-by-step explanation:
Airplane A's distance in miles to the airport can be written as ...
a = 30 -250t . . . . . where t is in hours
Likewise, airplane B's distance to the airport can be written as ...
b = 40 -300t
The distance (d) between the airplanes can be found using the Pythagorean theorem:
d^2 = a^2 + b^2
Differentiating with respect to time, we have ...
2d·d' = 2a·a' +2b·b'
d' = (a·a' +b·b')/d
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To find a numerical value of this, we need to find the values of its variables at t=0.
a = 30 -250·0 = 30
a' = -250
b = 40 -300·0 = 40
b' = -300
d = √(a²+b²) = √(900+1600) = 50
Then ...
d' = (30(-250) +40(-300))/50 = -19500/50 = -390
The distance between the airplanes is decreasing at 390 miles per hour.
Drawing out the triangle, we get the one below. We can use the trigonometric ratio of
tan to solve this problem.
x=21.5:)
Can I see the rest of the problem of number 18 please
Its the last one because you plug in the 20(x) for example y=20x
and your table looks like this
x 0/2/4
y 0/40/80 y x
because 20(2)=40 then you would do the same with the rest of the equation
20(4)= 80 there fore the last on is your answer
