Mathcad Problem - Solving Equations with Multiple Values

I'm sorry, but that multicolored link certainly did not help.

Its only the last line of calculations that gives me problems! sorry if its messy!

Multicolored?

I have an earlier version, MCAD 2000, which can't open the link. I'm not sure exactly what you mean, so I'll take a guess.

My thinking is that you want to set up a running variable with as many steps as you have previously-determined values and then create an array with these previously-determined values. The equations you want to solve would have to be written to accommodate arrays. For example:

Define the ORIGIN~1; then set i=:1,2...n where n is the the number of previously-determined values you have. Then create an array,

X_i =: 12 , 35 , 73 , 3.1416 , 137 (MCAD may show this as a column of data) Here there are five previously-determined values for X, so n=5.

You then define your equations to handle this data as an array.

Y_i=: cos(X_i) - [(X_i-2)² + sin(X_i)]³ + e^X_i

You will then get five values for Y.

Y=

-8.534 x 10⁵

1.172 x 10¹⁶

5.052 x 10³¹

19.927

3.15 x 10⁵⁹

Thanks for your answer:) Your guess was pretty close:) even though the circumstances are a bit different. I have a column of data, which is the result of a previously calculation, thereby defined as x[n Then i have an equation: x[n = ( sqrt(a[n-1)*(4a[n-1) ) / sqrt(3a[n-1) Now i want to solve for "a" as a function of the the previously calculated values of x. I would like it to use the x[n instead of punching them in manually. Hope it is possible. I have tried to save the file as a Mcad 11 version, follow new link: http://dl.dropbox.com/u/10626780/Problem%20-%20mathcad%2011%20version.xmcd By the way, how do you change line/make spacings on the posts?

Unless I'm missing something, that looks like simple algebra:

x_n = sqrt(a_n-1*4a_n-1) / sqrt(3a_n-1)

can be rewritten as:

a_n-1= 3(x_n²)/4

Since the left side is in n-1 and the right side is in n, you may need to add an extra term to your x_n values; maybe just add an extra zero.

To answer your other question -- The message box you type into has a text editor across the top. Click and drag the cursor over the text you want to edit then click the appropriate tool button (bold, italics, underscore, slashthrough, embed hyperlinks and so forth...) To add a vertical space, hit the Enter bar on your keyboard.

i think you've missed something, sorry

I have a column of data, which is the result of a previously calculation, thereby defined as x[n

Then i have an equation: x[n = ( sqrt(a[n-1)*(4a[n-1) ) / sqrt(3a[n-1)

Now i want to solve for "a" as a function of the the previously calculated values of x.

I would like it to use the x[n instead of punching them in manually.

(the "[n" after the parameters a and x, indicates that the it is a column of numbers)

Found out i couldn´t see the toolbar cause i was using Chrome!!! WTF?

Yeah I must be missing something...

I 'solved' your equation for a and equated it to x. I.e., I gave you an equation in the form:

a_n-1 = f(x_n)

Since your x_n values are already determined, the equation I gave you should yield your values for a as a function of these x values. You'll get a column of values for a corresponding to your column of values for x.

A more general solution can be obtained using 'Solve Blocks'. They are a bit more complicated to explain and to use. I don't have the time now to get into those. If you need more help try the Mathcad collaboratory.