Answer:
6,205 hours you are awake in a year
Step-by-step explanation:
If we write
where we see
in the equation and set the result equal to
, we get the result.
Answer:
1). The constant of variation is 7
2). w = 6 for the given values of x and y
Step-by-step explanation:
"Varies jointly" tells us that y is a direct result of a mathematic operation involving x and w. We will assume y is directly prorportional to x and w, in the sense that we can find a multiplicative relationship of the form y=Kxw, where K is the constant of variation.
We are given one data point: y=-42 where x is 2 and w is -3. Let's put those values into our trrial expression:
y=Kxw
-42=K(2)(-3)
-42 = -6K
K = 7
<h2>The expression becames <u>
y = 7xw</u></h2>
The constant of variation is 7.
The value of w for y=3 and x=(1/14) would be:
y=7xw
3 = 7*(1/14)*w
3 = (1/2)*w
<h2><u>
w = 6</u></h2>
Answer with Step-by-step explanation:
Given

Differentiating both sides by 'x' we get

Now we know that for an increasing function we have
![f'(x)>0\\\\14cos(2x)+7cos(x)>0\\\\2cos(2x)+cos(x)>0\\\\2(2cos^{2}(x)-1)+cos(x)>0\\\\4cos^{2}(x)+cos(x)-2>0\\\\(2cos(x)+\frac{1}{2})^2-2-\frac{1}{4}>0\\\\(2cos(x)+\frac{1}{2})^2>\frac{9}{4}\\\\2cos(x)>\frac{3}{2}-\frac{1}{2}\\\\\therefore cos(x)>\frac{1}{4}\\\\\therefore x=[0,cos^{-1}(1/4)]\cup [2\pi-cos^{-1}(1/4),2\pi ]](https://tex.z-dn.net/?f=f%27%28x%29%3E0%5C%5C%5C%5C14cos%282x%29%2B7cos%28x%29%3E0%5C%5C%5C%5C2cos%282x%29%2Bcos%28x%29%3E0%5C%5C%5C%5C2%282cos%5E%7B2%7D%28x%29-1%29%2Bcos%28x%29%3E0%5C%5C%5C%5C4cos%5E%7B2%7D%28x%29%2Bcos%28x%29-2%3E0%5C%5C%5C%5C%282cos%28x%29%2B%5Cfrac%7B1%7D%7B2%7D%29%5E2-2-%5Cfrac%7B1%7D%7B4%7D%3E0%5C%5C%5C%5C%282cos%28x%29%2B%5Cfrac%7B1%7D%7B2%7D%29%5E2%3E%5Cfrac%7B9%7D%7B4%7D%5C%5C%5C%5C2cos%28x%29%3E%5Cfrac%7B3%7D%7B2%7D-%5Cfrac%7B1%7D%7B2%7D%5C%5C%5C%5C%5Ctherefore%20cos%28x%29%3E%5Cfrac%7B1%7D%7B4%7D%5C%5C%5C%5C%5Ctherefore%20x%3D%5B0%2Ccos%5E%7B-1%7D%281%2F4%29%5D%5Ccup%20%5B2%5Cpi-cos%5E%7B-1%7D%281%2F4%29%2C2%5Cpi%20%5D)
Similarly for decreasing function we have
![[tex]f'(x)](https://tex.z-dn.net/?f=%5Btex%5Df%27%28x%29%3C0%5C%5C%5C%5C%5Ctherefore%20cos%28x%29%3C1%2F4%5C%5C%5C%5Cx%3Ccos%5E%7B-1%7D%28%5Cfrac%7B1%7D%7B4%7D%29%5C%5C%5C%5Cx%3D%5Bcos%5E%7B-1%7D%28%5Cfrac%7B1%7D%7B4%7D%29%2C2%5Cpi%20-cos%5E%7B-1%7D%28%5Cfrac%7B1%7D%7B4%7D%29%5D)
Part b)
To find the extreme points we equate the derivative with 0

Thus point of extrema is only 1.