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D( r )
r < 0
r < 0
r in <0:+oo)
r^(3/2)-(8*r^(1/2)) = 0
r^(3/2)-8*r^(1/2) = 0
t_1 = r^(1/2)
1*t_1^3-8*t_1^1 = 0
t_1^3-8*t_1 = 0
t_1*(t_1^2-8) = 0
1*t_1^2 = 8 // : 1
t_1^2 = 8
t_1^2 = 8 // ^ 1/2
abs(t_1) = 2*2^(1/2)
t_1 = 2*2^(1/2) or t_1 = -(2*2^(1/2))
t_1 = 0
t_1 = 0
t_1 = 2*2^(1/2)
r^(1/2)-(2*2^(1/2)) = 0
r^(1/2)-2*2^(1/2) = 0
1*r^(1/2) = -(-2*2^(1/2)) // : 1
r^(1/2) = 2*2^(1/2)
r^(1/2) = 2*2^(1/2) // ^ 2
r = 8
t_1 = -(2*2^(1/2))
r^(1/2)+2*2^(1/2) = 0
1*r^(1/2) = -(2*2^(1/2)) // : 1
r^(1/2) = -2*2^(1/2)
( -2*2^(1/2) < 0 i 1/2 in (0:1) ) => r należy do O
t_1 = 0
r^(1/2)+0 = 0
r^(1/2) = 0
1*r^(1/2) = 0 // : 1
r^(1/2) = 0
r = 0
r in { 8, 0 }
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