The positive factor of -72 is [72].
Answer:
cubic units
Step-by-step explanation:
We are to find the volume of the solid of revolution formed by rotating about the x--axis the region bounded by the given curves.
f(x)=2x+1, y=0, x=0, x=4.
The picture is given as shaded region.
This is rotated about x axis
Limits for x are already given as 0 and 4
f(x) is a straight line
The solid formed would be a cone
Volume = ![\pi \int\limits^a_b {(2x+1)^2} \, dx \\= \pi \int\limits^4_0 {(4x^2+4x+1)} \, dx \\=\pi [\frac{4x^3}{3} +2x^2+x]^5_0\\\\=\pi[\frac{4*4^3}{3}+2*4^2+4-0]\\=\frac{364\pi}{3}](https://tex.z-dn.net/?f=%5Cpi%20%5Cint%5Climits%5Ea_b%20%7B%282x%2B1%29%5E2%7D%20%5C%2C%20dx%20%5C%5C%3D%20%5Cpi%20%5Cint%5Climits%5E4_0%20%7B%284x%5E2%2B4x%2B1%29%7D%20%5C%2C%20dx%20%5C%5C%3D%5Cpi%20%5B%5Cfrac%7B4x%5E3%7D%7B3%7D%20%2B2x%5E2%2Bx%5D%5E5_0%5C%5C%5C%5C%3D%5Cpi%5B%5Cfrac%7B4%2A4%5E3%7D%7B3%7D%2B2%2A4%5E2%2B4-0%5D%5C%5C%3D%5Cfrac%7B364%5Cpi%7D%7B3%7D)
Answer:
156.25 grams
Step-by-step explanation:
Well, for starters we know that the substance decays by 2% each day and its been decaying for 34 days. Therefore, the substance has decayed by 68%
34 x 2 = 68
Hence, 50 grams is 32% because the substance has already decayed by 68%
100 - 68 = 32
So now we know 50 grams is 32%. Now we need to find how much 100% is.
50 - 32%
X - 100%
We cross multiply.
50 x 100 = 5000
And divide.
5000 / 32 = 156.25
Thus, in the beginning, there were 156.25 grams in the substance.
Hope this helps! :)
Usually test are worth 5-7% of your mark
Answer:
12 seconds
Step-by-step explanation:
75 t=66t+108
75t-66t=108
9t=108
t=108/9=12
