Integral

program ex625
!Enrique Ch Gabrick
!Resolver a integral de e^-x nos intervalos [0,1]
IMPLICIT NONE
DOUBLE PRECISION :: y, h, f
!INTEGER i
real x, dx, a, b, m, m0, i, g, x0, x1, x2, x3, y0, y1, y2, y3, d0, d1, d2, d3
real,parameter :: exp = 2.718281828

print *, 'Entre com o intervalo b e a'
read *, a,b
print *, 'Entre com o valor de m'
read *,m

if(m .eq. 0.00) stop 'valor ilegal de m'

open(unit=11,file='ex625.dat')

h = (b - a)/2
x0 = 0.25
x1 = 0.50
x2 = 0.75
x3 = 1.00

y0 = exp**(-x0)
y1 = exp**(-x1)
y2 = exp**(-x2)
y3 = exp**(-x3)

d0 = 1
d1 = 2
d2 = 2
d3 = 1


g = h/2*(d0*y0 + d1*y1 + d2*y2 + d3*y3)

write(11,*)g,y0,y1,y2,y3
close(11)

end program ex625