This value mast be a vector

[ptc-3682623]

Hi

I need help because I can"t solve my task. Please look at this situations. I need solve it vary guickly. Thanks for help

[RichardJ]

Assign x[N

[Werner_E]

You should realize that assiging 0 to x[N gives you a wrong result - a fifth order polynomiual which does not match your conditions. Richard had already advised you in the blog you created first that you have to decide which value to assign to get a correct result. If you assign the correct value, you get a result which closely matches the one you got using lsolve. See below and think about which value you would assign to x[7 when you would have to find the solutions manually.

I guess this is homework and you are forced to code the Gauß elimination yourself, right? Otherwise Mathcad would offer better ways and algorithms to get a solution.

[ptc-3682623]

Could You tell me Werner correct number of xn??

[ptc-3682623]

Could You sent me this solve in xmcd?

[Werner_E]

piotr grobelny wrote:

Could You sent me this solve in xmcd?

Here you are.

What do you think x[N should be?

[ptc-3682623]

I do not know what it should be

[Werner_E · Accepted solution]

Do you know how to solve a linear system of equations by hand using Gauß' method?

Did you program the routines in your sheet yourself?

You made the matrix a triangular matrix. How would you proceed when you are forced to solve the system by hand? What would be the first value you can immedeatly dertermine?

After all the last line reads:

0*x_1 + 0*x_2 + 0*x_3 + 0*x_4 + 0*x_5 + 0*x_6 + 1*x_7 = -1.04887*10^-14