TANGENT BUG

[andreasandreas6]

tan(10.4�) with correct spec of unit yields 0.139 in mathcad R14



sin (10.4�) is 0.181

and cos(10.4�) 0.984

quotient of which is 0.184, which is also what the tangent of 10.4� should be

[ValeryOchkov]

Val

http://twt.mpei.ac.ru/ochkov/v_ochkov.htm

[alnstevens]

Try tan(10.4deg)

stv

[ptc-1368288]

...



jmG

[IRstuff]

even tan(10.4[alt]0176) results in 0.1835

TTFN,
Eden

[TomGutman]

Post the sheet demonstrating the failure. It seems clear you've made some mistake, but it's not obvious what.
__________________
� � � � Tom Gutman

[andreasandreas6]

the sheet concerned is german. i played around with it a while.
these are the relations concerned. use of deg,� or rad makes no difference, it still appears to be a bug to me.it is a simple calculation relating to bolt torque, but i cannot post the sheet.

[RichardJ]

You are multiplying by degrees twice. If you have assigned Psi and Rho in degrees, just add them. Do not multiply the addition by degrees, because then what you get for Delta is

(Psi*deg + Rho*deg)*deg.

so you have units of deg^2.

Richard

[PhilipOakley]

On 11/19/2009 9:59:51 AM, rijackson wrote:
>You are multiplying by degrees
>twice. If you have assigned
>Psi and Rho in degrees, just
>add them. Do not multiply the
>addition by degrees, because
>then what you get for Delta
>is

(Psi*deg +
>Rho*deg)*deg.

so you have
>units of deg^2.

Richard

...which proves the need for the inclusion of 'angle' units ... 😉

Philip Oakley

[ptc-1368288]

On 11/19/2009 12:01:59 PM, philipoakley wrote:
...
>...which proves the need for the
>inclusion of 'angle' units ... 😉
____________________

No unit inclusion, no feature will ever change the mathematical numerical approximation of the trig functions, i.e: they are in rad. If you want them otherwise you append the result or define the definition in deg. No problem, just a matter of doing correct.



jmG

[ELSID]

jmG,
You are correct. But think of what is proposed as a help to some users. If you use the trig functions, then the results will return with a unit (rad). Then the user can change to degrees if needed. It will assist the user in trouble shooting. In Richards example, rad^2 would have been very apparent.

[ptc-1368288]

On 11/19/2009 1:09:00 PM, ElSid wrote:
>jmG,
You are correct. But
>think of what is proposed as a
>help to some users. If you
>use the trig functions, then
>the results will return with a
>unit (rad). Then the user can
>change to degrees if needed.
>It will assist the user in
>trouble shooting. In Richards
>example, rad^2 would have been
>very apparent.
_______________________________

Just read what I wrote and the meaning vs the construct. Why not construct as per the qs and the user manual ? Further, Mathcad does not calculate trig functions unless specifically requiring the symbolic engine. Trig functions are calculated by Pentium, they are in their corresponding form of approximation as listed in books or in other proven and reputed form recognized by the mathematical community.
The problem was miscarriage of the construct.

jmG