सदस्य: Melody

guest:
Dear Melody,

Thank you very much for your answer, is it correct if i only state --> TR = 12Q⁸ + 120Q⁶ + 450Q⁴ + 750Q²

because we don't know the value of "k" ?

It might be because it stands to reason that if Q=0 then TR will equal 0
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I think I would actually write,
"Since when Q=0, TR will also equal 0, k must be 0."
And then I would rewrite it leaving out the k.

(My logic behind this is that you cannot receive any revenue if you don't sell anything)

Melody27 Jan 2014

+118691

help:
Not math but science. If I'm trying to calculate mass with density and volume, assuming density is measured in kg/m^3, can my volume measurements be in cm or do I have to convert them to m?

I'd convert to metres.

Melody27 Jan 2014

+118691

[quote="guest"]Dear All,

Please help to check my answer of below question :

Question :

Marginal Revenue function of a product is = MR = 12Q (2Q ²+5) ³

Determine the Revenue function.

Answer :

TR = ∫ MR dQ
= ∫ 12Q (2Q ²+5) ³ dQ
Now you didn't expand your cubic properly.
(2Q ²+5)(2Q ²+5)(2Q ²+5)
= (2Q ²+5)(4Q ⁴+20Q ²+25)
= 8Q ⁶+40Q ⁴+50Q ²+20Q ⁴+100Q ²+125
= 8Q ⁶+60Q ⁴+150Q ²+125
Note: If I did this for myself I would use a binomial expansion but I thought you might not know how to do that. So I did it the long way.

Now you have:
TR = ∫ 12Q (8Q ⁶+60Q ⁴+150Q ²+125) dQ
TR = ∫ 96Q ⁷+720Q ⁵+1800Q ³+1500Q dQ

TR = 96/8 Q ⁸+720/6 Q ⁶ + 1800/4 Q ⁴ + 1500/2 Q ² + k
TR = 12Q ⁸ + 120Q ⁶ + 450Q ⁴ + 750Q ² + k (where k is a constant)

I think that this is correct now.

Melody27 Jan 2014

+118691

NewatAlgebra:
What is 8.37 multiplied by 10 to the -6th power?

All you have to do is move the decimal point over 6 places in the direction that will make the number smaller! (because the index is negative)
You will need to put a whole heap of zeros in like this

00000000008.37
I put in too many zeros but you can get rid of the ones you don't want later.
Now jump that decimal point over each digit, one at a time, until you have jumped over 6 digits altogether.
That will be your answer.
Just leave one zero in front of the point so that you can read it easily, you don't need or want any more than one zero in front of the point.
you finish this question and I will tell you if you got it right.

Melody27 Jan 2014

+118691

KaitlynGarrett99:
what is 0.000000090072 in scientific notation?

Hi Kaitlyn,
First you put 1 non zero digit in front of the decimal point so that's 9.0072

Now your number is really tiny so the exponent is going to be negative.
You have to jump over 8 digits (put the loops in, it helps) to get the point from where it is now to where you want it to be (that's after the nine)
so your answer is

9.0072 x 10 ^-8

Melody27 Jan 2014

+118691

Guest:
what is csc of theta=2.796

Cosec = 1/sine

To remember this I use the fact that the first letter in the usual ratio (sin, tan or cos)is the same as the 3rd letter in the reciprocal ratio. (in this cas the letter is s)
so
cosec =1/sine
cot = 1/tan
sec=1/cos

anyway
if cosec theta = 2.796 then
sin(theta) = 1 / 2.796

you can finish on your calculator, don't forget, you are looking for an angle so you have to press inv or 2nd

Melody27 Jan 2014

+118691

blahblahblah1:
The center of a line segment is at 5. If the line segment has length of 12, what is the sum of the end-points of the line segment?

This is a tricky question isn't it!?

The line is 12 units long so a half of it must be 6 units long.

If the interterval has 5 at its centre (on a number line ) then one end must be 5-6 and the other end must be 5+6.
That makes sense doesn't it. Draw it an take a look.
I think that you should be able to finish it.

Melody27 Jan 2014

+118691

nancy:
8500 to -1/3 power

Hi nancy,

8500 ^ (-1/3) = 0.04899973.....

= 0.049 (correct to 3decimal places or correct to 2 significant figures)

Melody27 Jan 2014

+118691

Hi imfifteen,
That was a great answer except that you made one little error with a sign and this was carried on down the problem,
I have used your solution because it is a good one but I have made some corrections in red

Hi Brownies,
Imfifteen has isolated s in the first equation then
substituted it into the second equation.
this means that you now have an equation with only r's in it. You have to solve this for r.
lastly you substitute your r into one of the early equations to get the value for s

imfifteen:
Let's say 5r-s=5 is equation 1 and -4+5s=17 is equation 2
In equation one you want to isolate s because it's easiest in this scenario.
First move the 5r to the right of the = sign so it becomes -s=-5r + 5
now you need to get rid of the negative on the s so multiply everything in the equation on both sides by -1
so it becomes s=+5r-5 I'll call this equation 3
now substitute that into equation 2 so it becomes -4+5(+5r-5)=17
it should become -4+25r-25=17, now move the 25 and -4 over to the right side of the = sign
it should become +25r=17+25+4
after adding it should be +25r=46
now you can divide both +25r and 46 by +25 because you want to isolate r
so it becomes r=+1.84

Now substitute r=1.84 into one of the the early equations to get the value of s. (Equation 3 would be easiest because s is already the subject)

Melody27 Jan 2014

यूजर का नाम	Melody
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