Answer:
13 ft/s
Step-by-step explanation:
t seconds after the boy passes under the balloon the distance between them is ...
d = √((15t)² +(45+5t)²) = √(250t² +450t +2025)
The rate of change of d with respect to t is ...
dd/dt = (500t +450)/(2√(250t² +450t +2025)) = (50t +45)/√(10t² +18t +81)
At t=3, this derivative evaluates to ...
dd/dt = (50·3 +45)/√(90+54+81) = 195/15 = 13
The distance between the boy and the balloon is increasing at the rate of 13 ft per second.
_____
The boy is moving horizontally at 15 ft/s, so his position relative to the spot under the balloon is 15t feet after t seconds.
The balloon starts at 45 feet above the boy and is moving upward at 5 ft/s, so its vertical distance from the spot under the balloon is 45+5t feet after t seconds.
The straight-line distance between the boy and the balloon is found as the hypotenuse of a right triangle with legs 15t and (45+5t). Using the Pythagorean theorem, that distance is ...
d = √((15t)² + (45+5t)²)
Answer:
180-146=34 146+34=180
Step-by-step explanation:
Answer:
Cos(2115°) =1/√2
Sin(2115°) = -1/√2
Step-by-step explanation:
We have to find the values of Cos (2115°) and Sin (2115°).
Now, 2115° can be written as (23×90°+ 45°).
Therefore, the angle 2115° lies in the 4th quadrant where Cos values are positive and Sin values are negative.
Hence, Cos (2115°) = Cos(23×90° +45°) =Sin 45° {Since 23 is an odd number, so the CosФ sign will be changed to SinФ} =1/√2 (Answer)
Again, Sin (2115°) = Sin(23×90° +45°) = -Cos 45° {Since 23 is an odd number, so the SinФ sign will be changed to CosФ} = -1/√2 (Answer)
Now, the required reference angle is 45°. (Answer)
Answer:
45231 = 
Step-by-step explanation:
Given the number:
45,231
We have To write the given number in the expanded form.
Solution:
First of all, let us write the different digits of the number:
Unit's digit = 1
Ten's digit = 3
Hundred's digit = 2
Thousand's digit = 5
Ten thousand's digit = 4
Unit's digit has to be multiplied with 1.
Ten's digit has to be multiplied with 10.
Hundred's digit has to be multiplied with 100.
Thousand's digit has to be multiplied with 1000.
Ten Thousand's digit has to be multiplied with 10000.
And then they have to be added so that the number gets formed.
45231 =
