1.
х+2х-48<0
Д=4-4*1*(-48)=196, 14
х=-2+;-14\2=-8;6
(х-6)(х+8)<0
___._____.___
-8. 6
х(-8;6)
<span>х² - 3х - 18= 0
D=b</span>²-4ac
D=(-3)² - 4*1*(-18)=81, 81>0, т.е. 2 корня.
x1 = (-b + VD)/2a
x1=(3+ V81)/2*1=(3+9)/2=6
<span>x2 = (-b - VD)/2a
</span>х2=(3-V81)/2*1=-3
Ответ: 6;-3
Cos(π/4 - x) > √3/2
cos(x - π/4) > √3/2
- arccos(√3/2) + 2πn < x - π/4 < arccos(√3/2) + 2πn, n∈z
- π/6 + 2πn < x - π/4 < π/6 + 2πn, n∈Z
- π/6 + π/4 + 2πn < x < π/6 + π/4 + 2πn, n∈Z
π/12 + 2πn < x < (5π)/12 + 2πn, n∈Z
X^2+3x-2x-6-x^2+3x-2x+6-5=6x-7
2x-5=6x-7
4x=2
x=1/2