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Rewrite – HP Prime Graphing Calculator User Manual

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330

Functions and commands

Differential

Equation

Returns the solution to a differential equation.

deSolve(Eq,[TimeVar],FncVar)

Example:

desolve(y''+y=0,y)

gives

c_0*cos(x)+c_1*sin(x)

ODE Solve

Returns an approximate value of y at a final value (t1) of a

given variable, where y(t) is the solution of: y’(t)=f(t,y(t)),

y(t0)=y0.

odesolve(Expr(f(t,y)),VectVar([t,y]),Vec
tInitCond([t0,y0]),FinalVal(t1),[tstep=V
al,curve])

Example:

odesolve(sin(t*y),[t,y],[0,1],2)

gives

[1.8224125572]

Linear System

Returns the solution to a system of linear equations.

linsolve(LstLinEq,LstVar)

Example:

linsolve([x+y+z=1,x-y=2,2*x-z=3],[x,y,z])

gives

[3/2,-1/2,0]

Rewrite

lncollect

Returns an expression rewritten with the logarithms collected.

(applies ln(a)+n*ln(b)->ln(a*b^n) for integers n).

lncollect(Expr)

Example:

lncollect(ln(x)+2*ln(y))

gives

ln(x*y^2)

powexpand

Returns an expression with a power of sum rewritten as a

product of powers.

powexpand(Expr)

Example:

powexpand(2^(x+y))

yields

(2^x)*(2^y)