0
2
4
6
8
10
0 0.1 0.2 0.3 0.4 0.5
cb
ca
cc
sum
0
2
4
6
8
10
0 0.1 0.2 0.3 0.4 0.5
cb
ca
cc
sum
0
40
80
120
0 0.004 0.008 0.012
©
©
0 0.5 1 1.5 2 2.5 3
-3
-2.5
-2
-1.5
-1
-0.5
0
x 10-4
©
xi
xi–1xi+1
xi–1/2 xi+1/2