1.23a=2.46a
1.23a-2.46a=0
-1.23a=0
a= 0\(-1.23)
a=0
===============
5t + 6(1 - t)(1 + t) = 5t + 6 - 6t² = (3 - 2t)(3t + 2).
![y= \frac{9}{x^2} +x; y'=(\frac{9}{x^2} +x)'=-\frac{18}{x^3} +1](https://tex.z-dn.net/?f=y%3D+%5Cfrac%7B9%7D%7Bx%5E2%7D+%2Bx%3B+y%27%3D%28%5Cfrac%7B9%7D%7Bx%5E2%7D+%2Bx%29%27%3D-%5Cfrac%7B18%7D%7Bx%5E3%7D+%2B1)
![y'=0: -\frac{18}{x^3} +1=0, x= \sqrt[3]{18} \ \textgreater \ 2= \sqrt[3]{8}](https://tex.z-dn.net/?f=y%27%3D0%3A+-%5Cfrac%7B18%7D%7Bx%5E3%7D+%2B1%3D0%2C+x%3D+%5Csqrt%5B3%5D%7B18%7D+%5C+%5Ctextgreater+%5C+2%3D+%5Csqrt%5B3%5D%7B8%7D+)
При x∈(0;2] y'<0, значит, функция убывает, принимая наибольшее значение при x→0, а наименьшее значение при x=2.
y_max = limy при x→0 = +∞; y_min=y(2)=9/4+1=3,25.
2cos^2 x - 1 = - cos x
cos x =-1; x=pi+pi*n
cox = 1/2; x=+-pi/3+2pi*n
корни в промежутке
-3pi;-2pi;-5pi/3;
Х+6/12=х/36 /12
(х+6)×3=х
3х+18=х
2х=-18
х=- 9