Answer:
The magnitude is 
The direction is
i.e toward the x-axis
Step-by-step explanation:
From the question we are told that
The function is 
The point considered is 
Generally the maximum rate of change of f at the given point and the direction is mathematically represented as
![\Delta f(x,y) = [\frac{\delta (9sin(xy))}{\delta x} i + \frac{\delta (9sin(xy))}{\delta y} i ]](https://tex.z-dn.net/?f=%5CDelta%20f%28x%2Cy%29%20%3D%20%20%5B%5Cfrac%7B%5Cdelta%20%20%289sin%28xy%29%29%7D%7B%5Cdelta%20x%7D%20i%20%20%2B%20%5Cfrac%7B%5Cdelta%20%20%289sin%28xy%29%29%7D%7B%5Cdelta%20y%7D%20i%20%20%20%5D)
![\Delta f(x,y) = [9y cos (x,y) i + 9xcos (x,y) j]](https://tex.z-dn.net/?f=%5CDelta%20f%28x%2Cy%29%20%3D%20%5B9y%20cos%20%28x%2Cy%29%20i%20%2B%20%209xcos%20%28x%2Cy%29%20j%5D)
At 
![\Delta f (0,8) = [9(8) cos(0* 8)i + 9(8) sin(0* 8)j ]](https://tex.z-dn.net/?f=%5CDelta%20%20f%20%280%2C8%29%20%3D%20%20%5B9%288%29%20cos%280%2A%208%29i%20%20%2B%209%288%29%20sin%280%2A%208%29j%20%20%5D)

There are 24 hours in a day, so if it chimes twice in an hour it will chime 24*2 or 48 times a day. There are 7 days in a week, so it will chime 48*7 or 336 times.
Answer:
x > 3
interval notation: (3, ∞)
Step-by-step explanation:
Given the inequality statement: 4x - 5 > 7,
The goal is to isolate x and find its solution.
Start by adding 5 to both sides:
4x - 5 + 5 > 7 + 5
4x > 12
Divide both sides by 4:
4x/4 > 12/4
x > 3
The solution can also be expressed in the following interval notation:
(3, ∞).
In terms of graphing, it involves an empty circle on the endpoint, x = 3, as it is not included as a solution. The solution to the given inequality statement must be greater than 3.
6.40x+9.90(154-x)=1230.90
Solve for x
X=84 for child
154-84=70 for adults