Finding BAC

[Michael Hill]

This is a javascript calculation problem

var ABC = 68.616; //degrees
var sinABC = Math.sin(ABC*Ma th.PI/180); //i.e. 0.93

var b = 4.123; //length of a long leg
var c = 4.37; //length of a hypotenuse

var sinBAC = (b*sinABC)/c; //i.e. .877

var BAC = ????????;

How do I convert sinBAC back to degrees using javascript?

BAC something around 61 degrees.....

Any help is appreciates.

Mike

[Andrew Urquhart]

Re: Finding BAC

*Michael Hill* wrote:[color=blue]
> This is a javascript calculation problem
>
> var ABC = 68.616; //degrees
> var sinABC = Math.sin(ABC*Ma th.PI/180); //i.e. 0.93
>
> var b = 4.123; //length of a long leg
> var c = 4.37; //length of a hypotenuse
>
> var sinBAC = (b*sinABC)/c; //i.e. .877
>
> var BAC = ????????;
>
> How do I convert sinBAC back to degrees using javascript?
>
> BAC something around 61 degrees.....
>
> Any help is appreciates.[/color]

Use Math.asin, and then convert radians to degrees. Whether the inverse
can give results in the wrong quadrant is left as an exercise for the
reader! :-)
--
Andrew Urquhart
- FAQ: www.jibbering.com/faq/
- Archive: www.google.com/groups?q=comp.lang.javascript
- My reply address is invalid, see www.andrewu.co.uk/contact/

[Michael Hill]

Re: Finding BAC



Michael Hill wrote:[color=blue]
>
> This is a javascript calculation problem
>
> var ABC = 68.616; //degrees
> var sinABC = Math.sin(ABC*Ma th.PI/180); //i.e. 0.93
>
> var b = 4.123; //length of a long leg
> var c = 4.37; //length of a hypotenuse
>
> var sinBAC = (b*sinABC)/c; //i.e. .877
>
> var BAC = ????????;[/color]

Hmmm I'm wondering if that means BAC = sinBAC*(180/Math.PI); //convert
to degrees ?????
[color=blue]
> How do I convert sinBAC back to degrees using javascript?
>
> BAC something around 61 degrees.....
>
> Any help is appreciates.
>
> Mike[/color]

[Michael Hill]

Re: Finding BAC

>[color=blue]
> Use Math.asin, and then convert radians to degrees. Whether the inverse
> can give results in the wrong quadrant is left as an exercise for the
> reader! :-)
> --[/color]

So you are saying ...

BAC = Math.asin(sinBA C)*180/Math.PI;