F'(x)=3x^2-6x
3x^2-6x=0 |:3
x^2-2x=0
x(x-2)=0
x1=0 x-2=0
x2=2
чертим прямую с интервалами:
----|------|----> x
+ 0 - 2 +
точка max- 0
точка min- 2
![\frac{3\pi }{2}<x<2\pi\\\\\frac{3\pi }{4}<x<\pi](https://tex.z-dn.net/?f=%5Cfrac%7B3%5Cpi%20%7D%7B2%7D%3Cx%3C2%5Cpi%5C%5C%5C%5C%5Cfrac%7B3%5Cpi%20%7D%7B4%7D%3Cx%3C%5Cpi)
x/2 - угол второй четверти, значит :
![Sin\frac{x}{2} >0;Cos\frac{x}{2}<0\\\\Sin\frac{x}{2}+Cos\frac{x}{2}+2,7=\sqrt{\frac{1-Cosx}{2} }-\sqrt{\frac{1+Cosx}{2}}+2,7=\sqrt{\frac{1-\frac{8}{13} }{2} }-\sqrt{\frac{1+\frac{8}{13} }{2}}+2,7=\sqrt{\frac{\frac{5}{13} }{2} }-\sqrt{\frac{\frac{21}{13} }{2} }+2,7=\sqrt{\frac{5}{26} } -\sqrt{\frac{21}{26} } +2,7](https://tex.z-dn.net/?f=Sin%5Cfrac%7Bx%7D%7B2%7D%20%3E0%3BCos%5Cfrac%7Bx%7D%7B2%7D%3C0%5C%5C%5C%5CSin%5Cfrac%7Bx%7D%7B2%7D%2BCos%5Cfrac%7Bx%7D%7B2%7D%2B2%2C7%3D%5Csqrt%7B%5Cfrac%7B1-Cosx%7D%7B2%7D%20%7D-%5Csqrt%7B%5Cfrac%7B1%2BCosx%7D%7B2%7D%7D%2B2%2C7%3D%5Csqrt%7B%5Cfrac%7B1-%5Cfrac%7B8%7D%7B13%7D%20%7D%7B2%7D%20%7D-%5Csqrt%7B%5Cfrac%7B1%2B%5Cfrac%7B8%7D%7B13%7D%20%7D%7B2%7D%7D%2B2%2C7%3D%5Csqrt%7B%5Cfrac%7B%5Cfrac%7B5%7D%7B13%7D%20%7D%7B2%7D%20%7D-%5Csqrt%7B%5Cfrac%7B%5Cfrac%7B21%7D%7B13%7D%20%7D%7B2%7D%20%7D%2B2%2C7%3D%5Csqrt%7B%5Cfrac%7B5%7D%7B26%7D%20%7D%20-%5Csqrt%7B%5Cfrac%7B21%7D%7B26%7D%20%7D%20%2B2%2C7)
1) y(x)=y(-3)=-2(-3)+3=6+3=9
y(x)=y(0)=3
2) 7=-2x+3
2x=3-7
2x=-4
x=-2
0=-2x+3
2x=3
x=1,5
ax=b
(-1/8)*x=1/4 //////////////////////
4x-3x=5/6+3/12-1/2
x=(10+3-6)/12
x=7/12