math
posted by enigma .
An initialvalue problem is given by the differential equation,
f(x,y) = x + y, y(0) = 1.64
The Eulermidpoint method is used to find an approximate value to y(0.1) with a step size of h = 0.1.
Then use the integrating factor method, to find the exact value of y(0.1).
Hence, determine the global error, giving your answer to 5 decimal places.
Note that Global Error = Approximate Value  Exact Value.

after calculating the y' and y'' values.
the values come up be 2.7731947639
which when rounded to 5 decimal places gives the answer as: 2.773195 
after recalculating the eulermidpoint method. the value I got was 1.8172 while using normal euler method is 1.968.
however, I can't seem to find the exact solution to minus off the 1.8172 value to get the global error.