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Since the component of force in the direction of movement is now Fcosθ, the work done is just FLcosθ

.

Do you mean 3 co-ordinate geometry points?  

Like find angle ABC given A and B and C.

Use the formula.

$$tan\alpha=\left|\frac{m_1-m_2}{1+m_1m_2}\right|$$

where

m1 is the gradient of of line AB and 

m2 is the gradient of line BC

@@ End of Day Wrap       Fri 21/11/14       Sydney,   Australia     Time 5:45 pm          ♬

Hi all,

Another very busy day on the forum.  But lots of great answers from Heureka, Mathematician, CPhill, Geno3141, happy7, BrittanyJ, Tiddle, DaMaster, QueenGreen and Roxy5306.  Thanks all.

I feel a bit guilty about the inerest posts because I know my answers are over represented. But I just don't have time to look at all questions and answers properly.  I really woud like you to message me is you see your own ro someone else's notworthy question or answer.  

Here is a few interest posts:

 1) The second indice question was a good one   Thanks Melody and Geno

Sat 22/11/14

There were many questions that did not get answered properly today - many but not of them were probablility.   I collected the address and put them in this thread. 

http://web2.0calc.com/questions/not-answered-or-not-answered-as-well-as-i-would-like-or-questions-that-could-do-with-checking

1) I liked this little physics question.  Thanks Alan

Umm I don't know about that one Chris 

62Kg is a mass not a weight.   (corrected)

1Kg=9.8N     ON EARTH

62Kg=607.6N    ON EARTH

Technically Jack can lift a maximum weight of   607.6N    (It would be the same on the alien planet)

That sounds right to me anyway  

(1/6)x-(1/12)y= -(1/2) <--Fractions  (1)

Mult both sides of (1) by 12 to get rid of the fractions

2x-1y=-6    (2)

2x-y=-6

Now these equations are identical so there is an infinite number of solutions.

If you graph them, they are the exact same line.    

Yes you are right mathematician  

Darla and Bill play a game where they pick 2 different numbers from the set {1, 2, 3, 4}. If the sum is larger than the product Darla wins. Otherwise Bill wins. What is the probability that Darla wins?

1,2      s=3    P=2      D

1,3      S=4    p=3     D

1,4      S=5    P=4      D

2,3       S=5   p=6       B

2,4       S=6   P=8         B

3,4       S=7    P=12      B

THE PROBABILTY THAT DARLA WILL WIN IS   1/2     OR     0.5     OR     50%

I've never heard the term alternate exterior angles

Alternate angles on parallel lines make a z shape and they are congruent (equal) to each other.

No other regular answerers are on a present.  I might be quicker to google your question.  

FV = 7300(1+0.035)^6

Interest = FV- 7300

3x^2 +2x-1=0

I am looking for 2 numbers that mult to 3*-1=-3   and add to +2

I see that the numbers are  -3 and +1

so now I will split 2x into  -3x+1x

$$\\3x^2 +2x-1=0\\
3x^2-3x +1x-1=0\\
3x(x-1) +1(x-1)\\
(3x+1)(x-1)=0$$

3x+1=0   or    x-1=0

3x=-1      or     x=1

x= -1/3    or     x=1

Okay

Sorry, not the stuff you have been presenting.

I can tackle some Australian business maths but I think you are using terms that are country based.

Anyway i am not familiar with the terms.

I'll  message you:)

how about 1 and 25

You don't know if b is the hypotenuse or the other short side so you can't definitively find it.

By definition a is the side opposite angle A

If b was the other short side then it would be the adjacent side 

and    tan15=347/b

etc

this has to be the third or the forth quad because sin is neg

In a first quad 'equivalent' triangle  opp=2, hyp=3  so adj = sqrt(9-4)=sqrt5

From here you should be able to name the other trig ratios. :)

The 1.1526 is correct to  4 decimal places.

So the phase of this complex number is the angle       $$tan^{-1}\left(\frac{9}{4}\right)\;\approx\; 1.1526$$

My knowledge of complex numbers is very rusty but I think all of this is correct.

Thank you =) 

Try looking at this clip

I think you would need to show us the whole question.

It makes no sense (to me) at the moment.  :))

There is no biggest number, there is always one that is bigger. 

There are numbers missing in your question 1

and

$$[24+9-(4\times 2) + 11]\div 2\\
=[24+9-8 + 11]\div 2\\
=[36]\div 2\\
=18$$

That was a good question anon 

3.00 x 10^8 / 6.50 x 10^-7

4.61 x 10^14

my question is how 10^8 / 10^-7 = 10^14?      IT DOES NOT!

$$\\(3\times 10^8)/(6.5\times 10^{-7})\\\\
=(3/6.5)\times 10^8/10^{-7}\\\\
=0.4615\times 10^{8--7}\\\\
=0.4615\times 10^{15}\\\\$$

BUT this answer is to be in scientific notation so there mus be just one non-zero number in front of the point

$$\\=4.4615\times 10^{-1} \times 10^{15}\\\\
=4.4615\times 10^{14}\qquad \mbox{Correct to 4 significant figures}\\\\$$

So does that all make sense now?

Do you mean "How many lots of 30 seconds are there in 60 minutes?

Well there is 2 lots in one minute so ther must be

120 lots in 60 minutes

$$85820 = Y + (Y \times 1.25\% + 30)\\

85820 = Y + Y \times 0.0125 + 30\\

85790 = Y + Y \times 0.0125 \\

85790 = Y \times 1.0125 \\

Y = 85790/1.0125$$