4/9 x 27 = girls
12 girls
5/9 x 27 = boys
15boys
Hey!
You have to use the Pythagorean Theorem
a² + b² = c²
a = 10
10² = 10 × 10 = 100
b = 11
11² = 11 × 11 = 121
100 + 121 = 221
√221 = 14.9(rounded)
Answer ⇒ 14.9
Hope this helps! :)
Answer:
a) -13.9 ft/s
b) 13.9 ft/s
Step-by-step explanation:
a) The rate of his distance from the second base when he is halfway to first base can be found by differentiating the following Pythagorean theorem equation respect t:
(1)
![\frac{d(D^{2})}{dt} = \frac{d(90 - x)^{2} + 90^{2})}{dt}](https://tex.z-dn.net/?f=%5Cfrac%7Bd%28D%5E%7B2%7D%29%7D%7Bdt%7D%20%3D%20%5Cfrac%7Bd%2890%20-%20x%29%5E%7B2%7D%20%2B%2090%5E%7B2%7D%29%7D%7Bdt%7D)
(2)
Since:
![D = \sqrt{(90 -x)^{2} + 90^{2}}](https://tex.z-dn.net/?f=%20D%20%3D%20%5Csqrt%7B%2890%20-x%29%5E%7B2%7D%20%2B%2090%5E%7B2%7D%7D%20)
When x = 45 (the batter is halfway to first base), D is:
![D = \sqrt{(90 - 45)^{2} + 90^{2}} = 100. 62](https://tex.z-dn.net/?f=%20D%20%3D%20%5Csqrt%7B%2890%20-%2045%29%5E%7B2%7D%20%2B%2090%5E%7B2%7D%7D%20%3D%20100.%2062%20)
Now, by introducing D = 100.62, x = 45 and dx/dt = 31 into equation (2) we have:
![\frac{d(D)}{dt} = -\frac{(90 - 45)*31}{100.62} = -13.9 ft/s](https://tex.z-dn.net/?f=%5Cfrac%7Bd%28D%29%7D%7Bdt%7D%20%3D%20-%5Cfrac%7B%2890%20-%2045%29%2A31%7D%7B100.62%7D%20%3D%20-13.9%20ft%2Fs)
Hence, the rate of his distance from second base decreasing when he is halfway to first base is -13.9 ft/s.
b) The rate of his distance from third base increasing at the same moment is given by differentiating the folowing Pythagorean theorem equation respect t:
![\frac{d(D^{2})}{dt} = \frac{d(90^{2} + x^{2})}{dt}](https://tex.z-dn.net/?f=%20%5Cfrac%7Bd%28D%5E%7B2%7D%29%7D%7Bdt%7D%20%3D%20%5Cfrac%7Bd%2890%5E%7B2%7D%20%2B%20x%5E%7B2%7D%29%7D%7Bdt%7D%20)
(3)
We have that D is:
![D = \sqrt{x^{2} + 90^{2}} = \sqrt{(45)^{2} + 90^{2}} = 100.63](https://tex.z-dn.net/?f=D%20%3D%20%5Csqrt%7Bx%5E%7B2%7D%20%2B%2090%5E%7B2%7D%7D%20%3D%20%5Csqrt%7B%2845%29%5E%7B2%7D%20%2B%2090%5E%7B2%7D%7D%20%3D%20100.63)
By entering x = 45, dx/dt = 31 and D = 100.63 into equation (3) we have:
![\frac{dD}{dt} = \frac{45*31}{100.63} = 13.9 ft/s](https://tex.z-dn.net/?f=%5Cfrac%7BdD%7D%7Bdt%7D%20%3D%20%5Cfrac%7B45%2A31%7D%7B100.63%7D%20%3D%2013.9%20ft%2Fs)
Therefore, the rate of the batter when he is from third base increasing at the same moment is 13.9 ft/s.
I hope it helps you!
<span>No because a negative times a negative will be positive and it will not equal a negative number. the square root cannot be one negative and one positive because that is against the definition of a square root.
</span>
Width = w
d)length in term of width
w + 5
b)
2(w + w + 5) > 30
2(2w +5)>30
c)
solve
2(2w +5) > 30
4w + 10 > 30
4w > 20
w > 5