Page 280 - Excel for Scientists and Engineers: Numerical Methods
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CHAPTER 1 1 ORDINARY DIFFERENTIAL EOUATIONS. PART I1 257
and the following named formulas were entered by using Insert-+Name+ Define.. .
left: =COLUMN(TopCell)
top: =ROW(TopCell)
Figure 11-1 1. Coefficients matrix to solve the second-order differential equation
y" - (0.15 - x/2.3)y = x by using the finite-difference method. The matrix is generated
fiom the matrix terms in column F of Figure 11-10, then Fill Right.
(folder 'Chapter 1 1 Examples', workbook 'ODE-BVP', worksheet 'Finite Difference 1')
The solution vector was produced by the array formula
{=MMULT(MINVERSE(l9:Ql7),G9:G17)}
Figure 11-12. Results vector for the second-order differential equation
y" - (0.15 - x/2.3)y = x solved by using the finite-difference method.
(folder 'Chapter 1 1 Examples', workbook 'ODE-BVP', worksheet 'Finite Difference 1')
