Step-by-step explanation:
You have to do first and second derivatives :
y = a sin 3x + b cos 3x
dy/dx = 3a cos 3x - 3b sin 3x
d²y/dx² = - 9a sin 3x - 9b cos 3x
Next, you have to compare it :
let d²y/dx² = ky,
-9a sin 3x - 9b cos 3x = k(a sin 3x + b cos 3x)
-9(a sin 3x + b cos 3x) = k(a sin 3x + b cos 3x)
Therefore, k is equals to 9.
It takes the faster pump 12 minutes to fill the tank.
Since the faster truck can produce 60% more than the other truck. 60% of 20 minutes is 12.
Cody ALONE = 8 hours
Kaitlyn ALONE = 6 hours
Let Joseph ALONE take j hours
Cody ALONE in 1 HOUR = 1/8 of the work Kaitlyn ALONE in 1 hour = 1/6 of the work Joseph ALONE in 1 HOUR = 1/j of the work
Since TOGETHER they take X hours, in 1 hour TOGETHER they complete 1 / X of the work
1/8 + 1/6 + 1/j = 1/X
1/j = 1/X - 1/8 - 1/6 = (24 - 3X - 4X ) /24X = (24 - 7X ) / 24X
j = 24X / ( 24- 7X )
After completing the work value of X will be known , calculate j from the above formula ANSWER
Answer:
If is positive, then the parabola opens upward, so the function decreases on and increases on . But if is negative, then just the reverse
