We know, that the <span>area of the surface generated by revolving the curve y about the x-axis is given by:
In this case a = 0, b = 15,
and:
So there will be:
![\left(\star\right)=\dfrac{2\pi}{15}\cdot\int\limits_0^{15}x^3\cdot\sqrt{1+\dfrac{x^4}{25}}\,\, dx=\dfrac{2\pi}{15}\cdot\dfrac{25}{6}\cdot\left[\left(1+\dfrac{x^4}{25}\right)^\frac{3}{2}\right]_0^{15}=\\\\\\= \dfrac{5\pi}{9}\left[\left(1+\dfrac{15^4}{25}\right)^\frac{3}{2}-\left(1+\dfrac{0^4}{25}\right)^\frac{3}{2}\right]=\dfrac{5\pi}{9}\left[2026^\frac{3}{2}-1^\frac{3}{2}\right]=\\\\\\= \boxed{\dfrac{5\Big(2026^\frac{3}{2}-1\Big)}{9}\pi}](https://tex.z-dn.net/?f=%5Cleft%28%5Cstar%5Cright%29%3D%5Cdfrac%7B2%5Cpi%7D%7B15%7D%5Ccdot%5Cint%5Climits_0%5E%7B15%7Dx%5E3%5Ccdot%5Csqrt%7B1%2B%5Cdfrac%7Bx%5E4%7D%7B25%7D%7D%5C%2C%5C%2C%20dx%3D%5Cdfrac%7B2%5Cpi%7D%7B15%7D%5Ccdot%5Cdfrac%7B25%7D%7B6%7D%5Ccdot%5Cleft%5B%5Cleft%281%2B%5Cdfrac%7Bx%5E4%7D%7B25%7D%5Cright%29%5E%5Cfrac%7B3%7D%7B2%7D%5Cright%5D_0%5E%7B15%7D%3D%5C%5C%5C%5C%5C%5C%3D%0A%5Cdfrac%7B5%5Cpi%7D%7B9%7D%5Cleft%5B%5Cleft%281%2B%5Cdfrac%7B15%5E4%7D%7B25%7D%5Cright%29%5E%5Cfrac%7B3%7D%7B2%7D-%5Cleft%281%2B%5Cdfrac%7B0%5E4%7D%7B25%7D%5Cright%29%5E%5Cfrac%7B3%7D%7B2%7D%5Cright%5D%3D%5Cdfrac%7B5%5Cpi%7D%7B9%7D%5Cleft%5B2026%5E%5Cfrac%7B3%7D%7B2%7D-1%5E%5Cfrac%7B3%7D%7B2%7D%5Cright%5D%3D%5C%5C%5C%5C%5C%5C%3D%0A%5Cboxed%7B%5Cdfrac%7B5%5CBig%282026%5E%5Cfrac%7B3%7D%7B2%7D-1%5CBig%29%7D%7B9%7D%5Cpi%7D)
Answer C.
</span>
Answer:
the two positive consecutive integers are 4 and 6.
Step-by-step explanation:
Let the smaller integer be s; then s^2 = (s + 2) + 10.
Simplifying, s^2 - s - 2 - 10 = 0, or
s^2 - s - 12 = 0.
Solve this by factoring: (s - 4)(s + 3) = 0.
Then s = 4 and s = -3.
If the first even integer is 4, the next is 6. We omit s = -3 because it's not even.
The smaller integer is 4. Does this satisfy the equation s^2 = (s + 2) + 10?
4^2 = (4 + 2) + 10 True or False?
16 = 6 + 10 = 16.
True.
So the two positive consecutive integers are 4 and 6.
Since we will be completing the square we need to isolate the x
y-5 = 2x^2 -4x
now we the coefficient of the x^2 to equal 1 so we take 2 as common factor
y-5 = 2(x^2 -2x)
now we'll make it perfect square by adding 2 to both sides
y-5+2=2(x^2-2x+1)
now simplify and convert the right side to squared expression
y-3 = 2(x-1)^2
now isolate the y
y = 2(x-1)^2 +3 that's it
Well I don't know.
Let's think about it:
-- There are 6 possibilities for each role.
So 36 possibilities for 2 rolls.
Doesn't take us anywhere.
New direction:
-- If the first roll is odd, then you need another odd on the second one.
-- If the first roll is even, then you need another even on the second one.
This may be the key, right here !
-- The die has 3 odds and 3 evens.
-- Probability of an odd followed by another odd = (1/2) x (1/2) = 1/4
-- Probability of an even followed by another even = (1/2) x (1/2) = 1/4
I'm sure this is it. I'm a little shaky on how to combine those 2 probs.
Ah hah !
Try this:
Probability of either 1 sequence or the other one is (1/4) + (1/4) = 1/2 .
That means ... Regardless of what the first roll is, the probability of
the second roll matching it in oddness or evenness is 1/2 .
So the probability of 2 rolls that sum to an even number is 1/2 = 50% .
Is this reasonable, or sleazy ?
It would take 4 hours for both trains to meet.
Speed is the ratio of distance travelled to time taken. It is given by:
Speed = distance / time
Let t represent the time at which both trains meet, and d represent the distance covered by train A, hence:
For train A:
100 = d / t
t = d/100
For train B:
200 = (1200 - d) / t
t = (1200 - d) / 200
d/100 = (1200 - d)/200
2d = 1200 - d
3d = 1200
d = 400 km
t = 400 / 100 = 4 hours
It would take 4 hours for both trains to meet.
Find out more at: brainly.com/question/22610586
