y= f(x)

y= 3x+2

y = f(x) + ε

y = 3x+2 + ε

y= a0+a1*x1+a2*x2+a3*x1^2+a4*x2^2+a5*x1*x2 + e

y1 x11 x21

y2 x12 x22

y3 x13 x23

…………….

yn x1n x2n

min suma [yi-( a0+a1*x1i+a2*x2i+a3*x1i^2+a4*x2i^2+a5*x1i*x2i)]^2

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