HP 48gII Uživatelský manuál stáhnout pdf (Strana 149)

Page 14-3

'X'

'XXX'

DE

The solution is:

which can be simplified to

y = K

⋅e

–3x

+ K

⋅e

+ K

⋅e

+ (450⋅x

+330⋅x+241)/13500.

Function DESOLVE

The calculator provides function DESOLVE (Differential Equation SOLVEr) to

solve certain types of differential equations. The function requires as input the

differential equation and the unknown function, and returns the solution to the

equation if available. You can also provide a vector containing the

differential equation and the initial conditions, instead of only a differential

equation, as input to DESOLVE. The function DESOLVE is available in the

CALC/DIFF menu. Examples of DESOLVE applications are shown below

using RPN mode.

Example 1

– Solve the first-order ODE:

dy/dx + x

⋅y(x) = 5.

In the calculator use:

'='

''

DEOE

The solution provided is

{‘y = (5*INT(EXP(xt^3/3),xt,x)+CC0)*1/EXP(x^3/3))’ }, which simplifies to

(

)

.)3/exp()3/exp(5)(

Cdxxxxy +⋅⋅−⋅=

∫

1 2 ... 144 145 146 147 148 149 150 151 152 153 154 ... 174 175

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HP 48gII Uživatelský manuál Strana 149