Coba mencari deret

Case 1
X
0
180
360
440







x1 = 0
x2 = x1 + 180
x3 = x2 + 180
x4 = x3 + 180

Jadi, eks-eks diatas xi = xi-2 + 180
kecuali x1. Is that simple? Yes! Apa ini disebut? Pengecualian!


Case 2
X 
0
180
360

Y
0
90
180

x1 = 0x2 = x1 + 180
x3 = x2 + 180
x4 = x3 + 180

dan

y1 = 0
y2 = 1/2 * x2
y3 = 1/2 * x3
y4 = 1/2 * x4

Jadi yi = 1/2 * xi kecuali y1. Simple!