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atan2(4,3)

$$\small{
\begin{array}{lcl}
\tan{(\alpha)} = \frac{a}{b} = \frac{\Delta y}{\Delta x}\\\\
\alpha = \mathbf{atan}{(\frac{a}{b}) }\\\\
\alpha =\mathbf{atan2} { ( a,b) } _{\text{in right quadrant}} =\mathbf{atan2}{ ( \text{numerator},\text{denominator} ) }
=\mathbf{atan2}{ ( \Delta y,\Delta x ) }\\
\end{array}
}$$

I already answered this somewhere else today !

Thanks Heureka,

Could you please tell me what this means?

Thank you Alan, that makes good sense.  I have not seen it before :))

The numbers being the  wrong way around is confusing.

I wonder why Mr Massow did that ?   (surely it is not normal)

if c is the midpoint of KN , what is KC?

$$\dfrac{\vec{N}-\vec{K}}{2} = \vec{KC}\\\\
\overline{KC} = |\vec{KC}|$$

Because she say   thank u so much 

Boys never say that. Only girls say that.

What is X= 5\2 = [5\2] = 2

OMG "Forget me Naughts" that is so funny.

I love those flowers too.

You said  Maybe she was eating "Forget me Zeros"

How did you know it's a girl?

Yes, that is excellent  DL :))

In some computer languages atan2(x,y) returns the angle between the origin and point (x,y), with the value returned being between ±180°.  In the calculator here, atan2(y,x) returns the angle between (x,y) and the origin.

So here:

$${atan2}{\left(\left({\mathtt{4}}\right), \left({\mathtt{3}}\right)\right)} = {\mathtt{53.130\: \!102\: \!354\: \!156^{\circ}}}$$  This is the angle whose y-component is 4 and whose x-component is 3

However, in Mathcad, for example atan2(4,3) = 36.87° which matches:

$${atan2}{\left(\left({\mathtt{3}}\right), \left({\mathtt{4}}\right)\right)} = {\mathtt{36.869\: \!897\: \!645\: \!844^{\circ}}}$$  This is the angle whose x-component is 4 and whose y-component is 3.

The desired result depends on which is x and which is y.  Only the poster will know!

.

atan2(4,3) ?

$$\mathbf{atan2}{(4,3)}=53.130102354156\ensurement{^{\circ}}\\
\Delta y = 4 \text{ and } \Delta x = 3$$

arctan with two parameters. see web2.0calculator. You can input like above.

OK I will re do it correctly.

8d⁶/g²

Yes that is true DL.  Teachers take special classes in forensic mathematics. 

I think Chris and Geno and Alan all did better than me in these classes but I still have more skill than most people who have not had any training. :)

8g^-2d^6

the 8 is not raised to a negative power, it has to stay up the top of the fraction :)

Oh, so you don't have Xray vision.  I am so disappointed DL.  I thought that you had special powers :(

Yes that is correct :)

50 x 1.52   mgm^2

and I expect your fingers work as well as mine do on the calc :)

[2nd] [atan]

Err how many seconds?  What country are we in ?  Maybe 84 years ?????

I only know because she put it in her follow up question. :)

Reading this is like listening the same piece of music sung by two different singers. Except this is written down. Heurekas math is always like art too. It is like looking at the sheet music.

I not know how to read music but I can read this and maybe understand it if I study it long enough.

YES I am sure that must be it!

OR

Maybe it is CPhill's fault.  He has not found the roman zero yet, maybe that is the zero anon wanted to use!

Maybe it really IS there  - but covered up by Harry's cloak of invisability??

You saw it DL.  Do you have special powers to see that which is invisable?

The first one can be 1,2 or 3

then there is 3 left for the next digit then 2 then only 1 for the last digit so

3*3*2*1 = 18

That is assuming it is a proper 4 digit number (it can't start with 0)

$$\\sec(\delta) = -6/5 tan(\delta)\\\\\\
\frac{1}{cos(\delta)}}=\frac{-6Sin(\delta)}{5cos(\delta)}\\\\
so\qquad \delta \ne n\pi\;\;radians \quad n\in Z\qquad and\\\\
1=\frac{-6Sin(\delta)}{5}\\\\
\frac{5}{-6}=sin(\delta)\\\\
\delta $must be in 3rd or 4th quadrant$\\
$but tan has to be neg so $\delta $ must be in the 4th quad $\\\\
\delta=asin(\frac{-5}{6})$$

$$\underset{\,\,\,\,^{\textcolor[rgb]{0.66,0.66,0.66}{360^\circ}}}{{sin}}^{\!\!\mathtt{-1}}{\left({\mathtt{\,-\,}}{\frac{{\mathtt{5}}}{{\mathtt{6}}}}\right)} = -{\mathtt{56.442\: \!690\: \!238\: \!079^{\circ}}}$$

$$\delta \approx -56^0\pm 360N\qquad where \quad N\in Z$$

Maybe she was eating "Forget me Zeros"

In British English it is "Forget me Naughts"

hahahahaha