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D( x )
(3-x)^2 = 0
(3-x)^2 = 0
(3-x)^2 = 0
3-x = 0 // - 3
-x = -3 // * -1
x = 3
x in (-oo:3) U (3:+oo)
45.9 = (2*x^2)/((3-x)^2) // - (2*x^2)/((3-x)^2)
45.9-((2*x^2)/((3-x)^2)) = 0
45.9-2*x^2*(3-x)^-2 = 0
(-2*x^2)/((3-x)^2)+45.9 = 0
(-2*x^2)/((3-x)^2)+(45.9*(3-x)^2)/((3-x)^2) = 0
45.9*(3-x)^2-2*x^2 = 0
43.9*x^2-275.4*x+413.1 = 0
43.9*x^2-275.4*x+413.1 = 0
43.9*x^2-275.4*x+413.1 = 0
DELTA = (-275.4)^2-(4*43.9*413.1)
DELTA = 275.4^2-72540.36
DELTA = 3304.8
DELTA > 0
x = ((275.4^2-72540.36)^(1/2)+275.4)/(2*43.9) or x = (275.4-(275.4^2-72540.36)^(1/2))/(2*43.9)
x = 0.01138952*((275.4^2-72540.36)^(1/2)+275.4) or x = 0.01138952*(275.4-(275.4^2-72540.36)^(1/2))
(x-0.01138952*(275.4-(275.4^2-72540.36)^(1/2)))*(x-0.01138952*((275.4^2-72540.36)^(1/2)+275.4)) = 0
((x-0.01138952*(275.4-(275.4^2-72540.36)^(1/2)))*(x-0.01138952*((275.4^2-72540.36)^(1/2)+275.4)))/((3-x)^2) = 0
((x-0.01138952*(275.4-(275.4^2-72540.36)^(1/2)))*(x-0.01138952*((275.4^2-72540.36)^(1/2)+275.4)))/((3-x)^2) = 0 // * (3-x)^2
(x-0.01138952*(275.4-(275.4^2-72540.36)^(1/2)))*(x-0.01138952*((275.4^2-72540.36)^(1/2)+275.4)) = 0
( x-0.01138952*((275.4^2-72540.36)^(1/2)+275.4) )
x-0.01138952*((275.4^2-72540.36)^(1/2)+275.4) = 0 // + -0.01138952*((275.4^2-72540.36)^(1/2)+275.4)
x = -(-0.01138952*((275.4^2-72540.36)^(1/2)+275.4))
x = 0.01138952*((275.4^2-72540.36)^(1/2)+275.4)
( x-0.01138952*(275.4-(275.4^2-72540.36)^(1/2)) )
x-0.01138952*(275.4-(275.4^2-72540.36)^(1/2)) = 0 // + -0.01138952*(275.4-(275.4^2-72540.36)^(1/2))
x = -(-0.01138952*(275.4-(275.4^2-72540.36)^(1/2)))
x = 0.01138952*(275.4-(275.4^2-72540.36)^(1/2))
x in { 0.01138952*((275.4^2-72540.36)^(1/2)+275.4), 0.01138952*(275.4-(275.4^2-72540.36)^(1/2)) }
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