HP 50g User Manual page 486

Performing the integration by hand, we can only get it as far as:
because the integral of exp(x)/x is not available in closed form.
Example 3 – Solving an equation with initial conditions. Solve
with initial conditions
In the calculator, use:
['d1d1y(t)+5*y(t) = 2*COS(t/2)' 'y(0) = 6/5' 'd1y(0) = -1/2'] `
Notice that the initial conditions were changed to their
= 6/5', rather than 'y(0)=1.2', and 'd1y(0) = -1/2', rather than, 'd1y(0) = -0.5'.
Changing to these Exact expressions facilitates the solution.
Note: To obtain fractional expressions for decimal values use function
(See Chapter 5).
The solution is:
Press μμto simplify the result to
'y(t) = -((19* 5*SIN( 5*t)-(148*COS( 5*t)+80*COS(t/2)))/190)'.
x
e
∫
( )
y x
x
e
∫
( )
y x dx
x
2 2
d y/dt + 5y = 2 cos(t/2),
y(0) = 1.2, y'(0) = -0.5.
'y(t)' `
DESOLVE
C
dx C
0
x
ln
C x C
0
Exact
expressions, 'y(0)
Q
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