Question

Rozwiąż nierówności:
a) 3x²-2x-1>0
b) 9x²-12x+4≤0
c) x²-2√2x+4>0

Answer 1

a) 3x²-2x-1>0

a = 3 b = -2 c=-2

delta = - 4ac

delta = 4-4*3*(-2)

delta = 4+24

delta = 28

=

x1 = 2- / 6 = 2-\sqrt{7}/3

x2 = 2+\sqrt{7}/3

 

b) 9x²-12x+4≤0

a = 9 b =-12 c=4

delta = 144-144

delta = 0

x = 12/18 = 2/3

 

c) x²-2√2x+4>0

2√2 c=4

delta = -4*1*4

delta = 8-16

delta = -8