Answer: C.
Explanation: i just took it. and got a 100. :)
Formula:
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<span>Note: , where nPr is the formula for permutations of n objects taken r at a time.</span>
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Example:
<span>How many different committees of 4 students can be chosen from a group of 15?
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Answer:
<span>There are possible combinations of 4 students from a set of 15.</span>
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There are 1365 different committees.</span></span></span>
<span>since sin and cos = each other at pi/4; take your integrals from 0 to pi/4
</span><span>[S] cos(t) dt - [S] sin(t) dt ;[0,pi/4]
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<span>to revolve it around the x axis;
we do a sum of areas
[S] 2pi [f(x)]^2 dx
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<span>take the cos first and subtract out the sin next; like cutting a hole out of a donuts.
</span><span>pi [S] cos(x)^2 dx - [S] sin(x)^2 dx ; [0,pi/4]
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<span>cos(2t) = 2cos^2 - 1
cos^2 = (1+cos(2t))/2
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<span>1/sqrt(2) - (-1/sqrt(2) +1)
1/sqrt(2) + 1/sqrt(2) -1
(2sqrt(2) - sqrt(2))/sqrt(2) = sqrt(2)/sqrt(2) = 1</span>
Answer:
Step-by-step explanation:
You can confirm this by working and expanding backwards:
Hope this helps!
