Y`(ctgx/3)`*(x/3)`=-1/3sin²(x/3)
y`(π)=-1/3sin²(π/3)=-1/(3*3/4)=-4/9
1)2sin²x+3sinx-2=0
sinx=z
2z²+3z-2=0,D=9+16=25,√D=√25=2
z1=(-3+2)/2=-1/2
z2=(-3-2)/2=-5/2=-2,5 ne dact rešenie
sinx=-1/2
a)x=7π/6+2kπ
b)x=11π/6+2kπ, k∈Z
2)2cos²x-5cosx-3=0
cosx=z
2z²-5z-3=0,D=25+24=49,√D=√49=7
z1=(5+7)/4=12/4=3, ne dact rešenie
z2=(5-7)/4=-2/4=-1/2
cosx=-1/2
a)x=2π/3+2kπ
b)x=4π/3+2kπ, k∈Z
3)tg²x-4tgx+3=0
tgx=z
z²-4z+3=0,D=16-12=4,√D=√4=2
z1=(4+2)/2=6/2=3
z2=(4-2)/2=2/2=1
a)tgx=3, x=arctg 3 +kπ
b)tgx=1, x=π/4+kπ, k∈Z
15-(6+7)=2
ответ:2 человека были из другого класса.
Она должна наказать черный автомобиль так как его скорость была равна 150км ч
<span>Найдём значение выражения:
- (</span><span>
- </span><span>
)=0,21) </span><span>
![\frac{9}{35}](https://tex.z-dn.net/?f=+%5Cfrac%7B9%7D%7B35%7D+)
-
![\frac{3}{28}](https://tex.z-dn.net/?f=+%5Cfrac%7B3%7D%7B28%7D+)
= </span>
![\frac{4*9}{4*35}](https://tex.z-dn.net/?f=+%5Cfrac%7B4%2A9%7D%7B4%2A35%7D+)
-
![\frac{5*3}{5*28}](https://tex.z-dn.net/?f=+%5Cfrac%7B5%2A3%7D%7B5%2A28%7D+)
=
![\frac{36}{140}](https://tex.z-dn.net/?f=+%5Cfrac%7B36%7D%7B140%7D+)
-
![\frac{15}{140}](https://tex.z-dn.net/?f=+%5Cfrac%7B15%7D%7B140%7D+)
=
![\frac{36-15}{140}](https://tex.z-dn.net/?f=+%5Cfrac%7B36-15%7D%7B140%7D+)
=
![\frac{36-15}{140}](https://tex.z-dn.net/?f=+%5Cfrac%7B36-15%7D%7B140%7D+)
=
![\frac{21}{140}](https://tex.z-dn.net/?f=+%5Cfrac%7B21%7D%7B140%7D+)
=
![\frac{7*3}{7*20}](https://tex.z-dn.net/?f=+%5Cfrac%7B7%2A3%7D%7B7%2A20%7D+)
=
![\frac{3}{20}](https://tex.z-dn.net/?f=+%5Cfrac%7B3%7D%7B20%7D+)
2)
![\frac{7}{20}](https://tex.z-dn.net/?f=+%5Cfrac%7B7%7D%7B20%7D+)
-
![\frac{3}{20}](https://tex.z-dn.net/?f=+%5Cfrac%7B3%7D%7B20%7D+)
=
![\frac{7-3}{20}](https://tex.z-dn.net/?f=+%5Cfrac%7B7-3%7D%7B20%7D+)
=
![\frac{4}{20}](https://tex.z-dn.net/?f=+%5Cfrac%7B4%7D%7B20%7D+)
=
![\frac{4}{4*5}](https://tex.z-dn.net/?f=+%5Cfrac%7B4%7D%7B4%2A5%7D+)
= <span>
![\frac{1}{5}](https://tex.z-dn.net/?f=+%5Cfrac%7B1%7D%7B5%7D+)
= 0,2</span>