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D( x )
(0.8-x)^2 = 0
(0.8-x)^2 = 0
(0.8-x)^2 = 0
0.8-x = 0 // - 0.8
-x = -0.8 // * -1
x = 0.8
x in (-oo:0.8) U (0.8:+oo)
(2*x)/((0.8-x)^2) = 53.3 // - 53.3
(2*x)/((0.8-x)^2)-53.3 = 0
(2*x)/((0.8-x)^2)+(-53.3*(0.8-x)^2)/((0.8-x)^2) = 0
2*x-53.3*(0.8-x)^2 = 0
87.28*x-53.3*x^2-34.112 = 0
87.28*x-53.3*x^2-34.112 = 0
87.28*x-53.3*x^2-34.112 = 0
DELTA = 87.28^2-(-53.3*(-34.112)*4)
DELTA = 87.28^2-7272.6784
DELTA = 345.12
DELTA > 0
x = ((87.28^2-7272.6784)^(1/2)-87.28)/(-53.3*2) or x = (-(87.28^2-7272.6784)^(1/2)-87.28)/(-53.3*2)
x = -0.00938086*((87.28^2-7272.6784)^(1/2)-87.28) or x = 0.00938086*((87.28^2-7272.6784)^(1/2)+87.28)
(x+0.00938086*((87.28^2-7272.6784)^(1/2)-87.28))*(x-0.00938086*((87.28^2-7272.6784)^(1/2)+87.28)) = 0
((x+0.00938086*((87.28^2-7272.6784)^(1/2)-87.28))*(x-0.00938086*((87.28^2-7272.6784)^(1/2)+87.28)))/((0.8-x)^2) = 0
((x+0.00938086*((87.28^2-7272.6784)^(1/2)-87.28))*(x-0.00938086*((87.28^2-7272.6784)^(1/2)+87.28)))/((0.8-x)^2) = 0 // * (0.8-x)^2
(x+0.00938086*((87.28^2-7272.6784)^(1/2)-87.28))*(x-0.00938086*((87.28^2-7272.6784)^(1/2)+87.28)) = 0
( x+0.00938086*((87.28^2-7272.6784)^(1/2)-87.28) )
x+0.00938086*((87.28^2-7272.6784)^(1/2)-87.28) = 0 // - 0.00938086*((87.28^2-7272.6784)^(1/2)-87.28)
x = -(0.00938086*((87.28^2-7272.6784)^(1/2)-87.28))
x = -0.00938086*((87.28^2-7272.6784)^(1/2)-87.28)
( x-0.00938086*((87.28^2-7272.6784)^(1/2)+87.28) )
x-0.00938086*((87.28^2-7272.6784)^(1/2)+87.28) = 0 // + -0.00938086*((87.28^2-7272.6784)^(1/2)+87.28)
x = -(-0.00938086*((87.28^2-7272.6784)^(1/2)+87.28))
x = 0.00938086*((87.28^2-7272.6784)^(1/2)+87.28)
x in { -0.00938086*((87.28^2-7272.6784)^(1/2)-87.28), 0.00938086*((87.28^2-7272.6784)^(1/2)+87.28) }
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