Thread: Need some Help with MathCad :)

Hey all, Just wondering if anyone uses mathcad prime 1.0?

I'm using it at the moment and trying to find the co-efficients of an 8th order polynomial using boundary conditions.

if anyone can help me set up and solve this equation it would be much appreciated!

Thanks!

Here is the equation:

(@EQ (@LABEL VARIABLE L) (+ (+ (+ (+ (+ (+ (+ (+ (* (@LABEL VARIABLE A) (^ θ 8)) (* B (^ θ 7))) (* C (^ θ 6))) (* D (^ θ 5))) (* E (^ θ 4))) (* F (^ θ 3))) (* G (^ θ 2))) (* H θ)) I))

Ok cant just copy paste I see!

Are the various values of randomly spaced or are they evenly spaced ? What do you mean by boundary condotions in this context ?

I have only 3 boundary conditions:

if x= 90 then L= 11.5, if x=45 then L=11.5/2 if L=0 then x=0

As for how the constants are spaced I have no idea.
x is actually theta but I couldnt find that here. x is an angle

Its for a Cam design project

You have nine unknown coefficients, that means that you need nine pairs of values for and to determine all of them uniquely.

No other way at all?

Guess some inbetween Ls and x's?

You could do if that is acceptable to your design. Can you make use of symmetry in some way ? Is it symmetrical about some axis ? If you do manage to generate some more points, calculations are easier if the values are equally spaced. BTW, I know nothing about MathCad. What we are talking about is independent of MathCad (or any other calculating device).

Awesome, thanks Bob, I'm sure there is a way to do this I just don't know what I'm about really! Thanks for your help Bob- I will see if i can gather more info before I bother you guys again! Sorry about this.

With your specified 3 boundary values it is possible to eliminate 3 of coefficients and obtain the following result: