All Answers 358087 Answers

I was on too!

I think this is meant to be

 $$1-\sin a=\frac{\cot a - \cos a}{\cot a}$$

$$\frac{\cot a - \cos a}{\cot a}=1-\frac{\cos a}{\cot a}=1-\frac{\cos a}{\cos a/\sin a}=1-\sin a$$

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This is a well-known series whose sum is finite and equals 2

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I think the use of E to denote exponent began in ancient times when cavemen used to program computers using the FORTRAN computing language using punched tape or punched cards.  There was a fixed limit to the number of characters that could be punched on a line of coding (∼60 I think) so anything to save space was useful, and E rather than *10^ saved a few characters.  

The E was used where single-precision calculations were required; the letter D was used to mean the same thing for double-precision calculations.

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$$\\\sqrt{250}-\frac{\sqrt{40}}{\sqrt2}\\\\
=\sqrt{250}-\frac{\sqrt{40}\sqrt2}{2}\\\\
=\sqrt{25}\sqrt{10}-\frac{\sqrt{10}\sqrt4\sqrt2}{2}\\\\
=5\sqrt{10}-\frac{\sqrt{10}*2*\sqrt2}{2}\\\\
=5\sqrt{10}-\sqrt{5}\sqrt2\sqrt2\\\\
=5\sqrt{10}-2\sqrt{5}\\\\$$

$${\mathtt{132}}{\mathtt{\,\times\,}}\left({\mathtt{123\,368}}{\mathtt{\,-\,}}{\mathtt{33}}{\mathtt{\,\times\,}}{\mathtt{y}}\right) = {\mathtt{66}}{\mathtt{\,\times\,}}\left({\mathtt{249\,103}}{\mathtt{\,-\,}}{\mathtt{27}}{\mathtt{\,\times\,}}{\mathtt{y}}\right) \Rightarrow {\mathtt{y}} = {\mathtt{\,-\,}}{\frac{{\mathtt{789}}}{{\mathtt{13}}}} \Rightarrow {\mathtt{y}} = -{\mathtt{60.692\: \!307\: \!692\: \!307\: \!692\: \!3}}$$

Use the calc on the home page.

Make sure the button on the bottom left corner is set to radians.

then press

 [2nd] [asin] 0.55=

NOTE:  that asine is the same as inverse sine

@@ End of Day Wrap           Fri 5/12/14         Sydney,   Australia          Time 10:55 am         ♬

Good evening, it is morning you say?  No it is dark so it cannot be morn.  

This is a website that I really like.  It has many nice features but the one Ilike the best is an interactive map so that I can easily see what time it is anywhere in the world.  I use this site every day.

nice 

Now I get it 

Thank you 

Sat 6/12/14

1) A little riddle   Thanks Happy and anon  

Both are true when    $$x<-2$$                          $$(-\infty,-2)$$

1-sina = ctga - cosa / ctga     ???

1 - sin a   =  cos a / sin a    - cos a / (cos a / sin a)   ???

1 - sin a = cos a / sin a  - sina     add sin a to both sides

1 = cos a / sin a  ????    

Nope.......not an identity.......

"C"   looks good......rent < 3000 for Chicago   .... > 2900 for Tokyo  ......

-2<2(x-1)<3   divide everything by 2, first

-1 < x-1 < 3/2     add 1 to everything

0 < x < 5/2

In interval notation, we have

(0, 5/2 ]

Huh. Alrighty then. Thanks very much, guys.

You have to get them all to one side an  = 0 first.

eg

$$\\2(x - 3)^2 = -2x + 9\\
2(x - 3)(x-3) = -2x + 9\\
2(x^2-6x+9) = -2x + 9\\
2x^2-12x+18 = -2x + 9\\
2x^2-12x+2x+18-9 = -2x+2x + 9-9\\
2x^2-10x+9 = 0\\\\
a=2,\;\; b=-10,\;\; c=9$$

No....we want everything on the same side  - I prefer the left side, myself

For instance....this one...

-(x^2) +1 = -5(x^2) + 4x        add 5x^2 to both sides and subtract 4x from both sides

4x^2 - 4x + 1 = 0      so...a = 4 b = -4 and c = 1     (got it ???)

(Actually....I wouldn"t even use the Q formula on this one....it can be factored and solved directly.....!!!.......but if that's what they're asking you to do.....)

I'll take it Chris :)

Well, if you wouldn't mind helping w/ one of those two-sided ones, that'd be great. Is it done the same way, just using the formula on both sides?

Shadew.....let us know if you have trouble putting any of them in S.F.......once you do that....it's just "plug and play," basically.......

2x>5 or -(5/7)x-4>7

2x>5     divide both sides by 2

x > 5/2

-(5/7)x-4>7       add 4 to both sides

-5/7x > 11        multiply both sides by -7/5  and reverse the inequality sign

x < -77/5

"Or"  usually means "Union"

So....the solution set is

(-∞, -77/5) U [5/2, ∞)

Well, to be fair, that isn't all of it.

But I seriously thought the point of this site was to get help with math homework. Granted, I could (and should) have just asked for you guys to answer one and then applied the steps to the rest.

This doesn't make any sense to me....... an angle of 9 degrees???.....what are you referring to???

We don't know how to stop it.  It just does that sometimes.  

If it does it for you really badly maybe it has got something to do with using colour.

It doesn't happen to me very often and i do not use colour much.

It's probably irrelevant.  Just an observation.   

`1/6*100  now you can do it on a calculator