How to solve Differential Equations

 HP48/49 are able to find a solution y(T), to a differential equation expressed as y'( T ) = f (T,y), where the initial value of the function is given as y(to)=yo. HP48/49 are able to solve differential equations in the numeric mode only. Example: Solve the Differential Equation y' ( T ) = y + COS( T ) for y( 0 ) = 0 given that y( 0 ) = 0 1 - write the Differential Equation in the field f 2-Access Solve Application: Press: [NUM SLV] if you are using HP49. [SOLVER] if you are using HP48. and choose 2-Solve dif eq.. 3 - write the Differential Equationin the field f 4 - enter independent and dependent variables, the limits and press [SOLVE] Press [ENTER] to see the result in the stack What are the variables enclosed? Variables enclosed are to, t and yo Given a differential equation y'( T ) = y + COS( T ) to solve it for y( T ) given that y ( to ) = yo the variables can be written as in the picture beside. Example Solve the Differential Equation y'( T ) = y + COS( T ) for y( 3 ) given that y ( 1 ) = 2 Result:14.2307048559 