My triangle solver says EF ≈ 7.5 ft.
_____
The law of cosines is usually used for this.
EF^2 = DE^2 +DF^2 -2*DE*DF*cos(D)
.. = 6^2 +11^2 -2*6*11*cos(40°)
.. ≈ 55.88
EF ≈ √55.88 ≈ 7.5 . . . ft
The 3 in 24,345 has a value of 300. A number 10 times that would have a value of 300*10 or 3,000. The 3 in choice C has a value of 3,000 so C is the right answer.
The question is:
Check whether the function:
y = [cos(2x)]/x
is a solution of
xy' + y = -2sin(2x)
with the initial condition y(π/4) = 0
Answer:
To check if the function y = [cos(2x)]/x is a solution of the differential equation xy' + y = -2sin(2x), we need to substitute the value of y and the value of the derivative of y on the left hand side of the differential equation and see if we obtain the right hand side of the equation.
Let us do that.
y = [cos(2x)]/x
y' = (-1/x²) [cos(2x)] - (2/x) [sin(2x)]
Now,
xy' + y = x{(-1/x²) [cos(2x)] - (2/x) [sin(2x)]} + ([cos(2x)]/x
= (-1/x)cos(2x) - 2sin(2x) + (1/x)cos(2x)
= -2sin(2x)
Which is the right hand side of the differential equation.
Hence, y is a solution to the differential equation.
Answer:
42
Step-by-step explanation:
4+6 = 10
10+7 = 17
17+2 = 19
19+9 = 28
28+2 = 30
30+9 = 39
39+3 = 42
Answer: 18 males and 15 females
Step-by-step explanation: Good luck! :D
