Answer:
It would be 8
Step-by-step explanation:
20% of 40 is 8
Answer:
![\frac{dh}{dt}=\frac{30r}{\sqrt{d^{2}+900}}](https://tex.z-dn.net/?f=%5Cfrac%7Bdh%7D%7Bdt%7D%3D%5Cfrac%7B30r%7D%7B%5Csqrt%7Bd%5E%7B2%7D%2B900%7D%7D)
Step-by-step explanation:
A road is perpendicular to a highway leading to a farmhouse d miles away.
An automobile passes through the point of intersection with a constant speed
= r mph
Let x be the distance of automobile from the point of intersection and distance between the automobile and farmhouse is 'h' miles.
Then by Pythagoras theorem,
h² = d² + x²
By taking derivative on both the sides of the equation,
![(2h)\frac{dh}{dt}=(2x)\frac{dx}{dt}](https://tex.z-dn.net/?f=%282h%29%5Cfrac%7Bdh%7D%7Bdt%7D%3D%282x%29%5Cfrac%7Bdx%7D%7Bdt%7D)
![(h)\frac{dh}{dt}=(x)\frac{dx}{dt}](https://tex.z-dn.net/?f=%28h%29%5Cfrac%7Bdh%7D%7Bdt%7D%3D%28x%29%5Cfrac%7Bdx%7D%7Bdt%7D)
![(h)\frac{dh}{dt}=rx](https://tex.z-dn.net/?f=%28h%29%5Cfrac%7Bdh%7D%7Bdt%7D%3Drx)
![\frac{dh}{dt}=\frac{rx}{h}](https://tex.z-dn.net/?f=%5Cfrac%7Bdh%7D%7Bdt%7D%3D%5Cfrac%7Brx%7D%7Bh%7D)
When automobile is 30 miles past the intersection,
For x = 30
![\frac{dh}{dt}=\frac{30r}{h}](https://tex.z-dn.net/?f=%5Cfrac%7Bdh%7D%7Bdt%7D%3D%5Cfrac%7B30r%7D%7Bh%7D)
Since ![h=\sqrt{d^{2}+(30)^{2}}](https://tex.z-dn.net/?f=h%3D%5Csqrt%7Bd%5E%7B2%7D%2B%2830%29%5E%7B2%7D%7D)
Therefore,
![\frac{dh}{dt}=\frac{30r}{\sqrt{d^{2}+(30)^{2}}}](https://tex.z-dn.net/?f=%5Cfrac%7Bdh%7D%7Bdt%7D%3D%5Cfrac%7B30r%7D%7B%5Csqrt%7Bd%5E%7B2%7D%2B%2830%29%5E%7B2%7D%7D%7D)
![\frac{dh}{dt}=\frac{30r}{\sqrt{d^{2}+900}}](https://tex.z-dn.net/?f=%5Cfrac%7Bdh%7D%7Bdt%7D%3D%5Cfrac%7B30r%7D%7B%5Csqrt%7Bd%5E%7B2%7D%2B900%7D%7D)
Cid Sam is a way to remember
C -control S - SAME (keep the same)
I -independent A- alter
D-depend M- measure
independent- number of downloads
Dependant - money spent
Answer:
$0.91.
91 cents.
Step-by-step explanation:
have a good day!
Given:
Schaum's earnings in a month = ![x^4+16x](https://tex.z-dn.net/?f=x%5E4%2B16x)
His wife's earnings in a month = ![3x^4+11x](https://tex.z-dn.net/?f=3x%5E4%2B11x)
Where x is the number of working days in a month.
To find:
The total earnings in a month.
Solution:
We know that,
Total earnings = Schaum earnings + His wife's earnings in a month
![=x^4+16x+3x^4+11x](https://tex.z-dn.net/?f=%3Dx%5E4%2B16x%2B3x%5E4%2B11x)
![=(x^4+3x^4)+(16x+11x)](https://tex.z-dn.net/?f=%3D%28x%5E4%2B3x%5E4%29%2B%2816x%2B11x%29)
![=4x^4+27x](https://tex.z-dn.net/?f=%3D4x%5E4%2B27x)
Therefore, the correct option is A.