Explicație pas cu pas:
x-7y+3=0 => x=7y-3
V(x²+y²+6x+9)+V(x²+y²-8x-2y+17)=
V[(x+3)²+y²] + V(x²-8x+16 +y²-2y+1)=
V[(7y-3+3)²+y²] + V[(x-4)²+(y-1)²] =
V[(7y)²+y²]+V[(7y-3-4)²+(y-1)²] =
V(49y²+y²) + V[(7y-7)²+(y-1)²]=
V(50y²)+V[7(y-1)]²+(y-1)²(totul sub radical) = |y|V50 + V[49(y-1)²+(y-1)²] =
|y|V50 + V[50(y-1)²] =
|y|V50 + |y-1|V50 = V50(|y|+|y-1|)
x€[-3,4] => -3<=x<=4 => -3<=7y-3<=4 =>
0<=7y<=7 => 0<=y<=1 => y>=0 si y-1<=0
=> E=V50(y+1-y) => E=V50 => E=5V2 ( constant)
