Melody

There are some really neat questions in that lot Jillybean.  Thanks  :)

Rosala, they just want

88*69/35

which can be done in the calc on the home page

just enter

atan(3)

Maybe this will help

 the corrected diagram is on a post below.

Prob that neither increase is  5/18

They are very unlikely to be independent events because the market tends to be either up or down over any given period of time, pluys if one company is going broke then its competitor might be doing really well.

  However if the companies are not in the same sector (similar field) or in the same country they would be more independent than otherwise.

If it was an isosceles right triangle you could do it but then of course you really do know the other angles. :)

inverse cos (7/18)

or

acos(7/18)     it is the same thing.

just type in

asin(0.606)

arc sin is the same as inverse sine 

I really have no idea if this is at all relevant - I suppose I should google it.     LOL

I saw the word rate so I differentiated .    

$$\frac{d}{dx}(sinx)*x^{-1}\\\\
=(sinx)*-1x^{-2}\;+\;(cosx)*x^{-1}\\\\
=\frac{-sin(x)}{x^2}\;+\;\frac{cos(x)}{x}\\\\
=\frac{xcos(x)-sin(x)}{x^2}$$