cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
Showing results for 
Search instead for 
Did you mean: 

Community Tip - Stay updated on what is happening on the PTC Community by subscribing to PTC Community Announcements. X

How can I set trigonometric functions to be in degrees (nor radians)?

nvsuryan
1-Newbie

How can I set trigonometric functions to be in degrees (nor radians)?

I am working on problems where all the angles are in degrees and the trigonometric functions should read them as such. It is a lot of work to make sure that all the angles are converted to radians before the algebraic expressions involving them are evaluated. Is there any way that a statement or preference can be added so that mathcad correctly evaluates the trigonometric functions with the arguments in degrees?

7 REPLIES 7

sin(90 deg)=1 m/m

cos(90 deg)=1m/m

asin(1 m/m)=1.572 rad

asin(1 m/m)=90 deg

asin(1 m/m)=100 grad

etc

Or you can use Mathcad Prime Minister

Rad Deg Grad Etc

There is no option to change the default (pseudo)unit of angle to something else than radian.

If you want a length to be in meter you write m, if it shoul be interpreted as feet you write ft.

The same applies to the pseudounits of "dimension"  angle. If you want a quantity in degree, you have to write "deg" or "°".

If you want it in radian you either write "rad" or nothing at all, as rad=1.

If you are using the symbolics they don't know anything about units and will treat deg or ° as unknown variable. So you would have to define °:=pi/180 and/or deg:=pi/180 yourself.

Werner Exinger wrote:

as rad=1.

Sorry, rad=1 m/m

or

rad=3.281 ft/m

etc

Valery Ochkov wrote:

Werner Exinger wrote:

as rad=1.

Sorry, rad=1 m/m

... and m/m is ...?

The ratio of two lengths is a dimensionless number, in our case rad=1.

It doesn't matter if you measure in meter or feet or mixed length units.

Mathcad knows about that ;.)

An unit of specific enthalpy in not m^2/s^2 but J/kg

An unit of thermal conductivity is not J/(m K) but J*m/(m^2*K)

Etc (rad=m/m, for example)

We sometime do simplify units but it is not good for education!

And for industrial calculation too - rad+sr=2, rad+%=1.01 etc but must be an error message!

Units system in Mathcad is not quit absolute good

rad+%=1.01 etc but must be an error message!

No! Its perfectly correct from a mathematical point of view rad and % are just dimensionless numbers, nothing more.

StuartBruff
23-Emerald II
(To:nvsuryan)

Narasipur Suryanarayana wrote:

I am working on problems where all the angles are in degrees and the trigonometric functions should read them as such. It is a lot of work to make sure that all the angles are converted to radians before the algebraic expressions involving them are evaluated. Is there any way that a statement or preference can be added so that mathcad correctly evaluates the trigonometric functions with the arguments in degrees?

Either use the built-in unit conversion facility or redefine the trig function to work in degrees.

Stuart

Top Tags