Множества совпадают тогда , когда
![aa_{1} = bb_{1} \\ aa_{2} = bb_{2} \\ ... \\ aa_{n} = bb_{n} \\\\ \frac{a}{b} = \frac{b_{1}}{a_{1}} = \frac{b_{2}}{a_{2}} ... = \frac{b_{n}}{a_{n}} \\ b_{n} = ax \\ a_{n} = bx \\ ](https://tex.z-dn.net/?f=++aa_%7B1%7D+%3D+bb_%7B1%7D+%5C%5C%0A+++++++aa_%7B2%7D+%3D+bb_%7B2%7D+++++++%5C%5C%0A++++++++++++...+%5C%5C%0A+++++++++aa_%7Bn%7D+%3D+bb_%7Bn%7D+++++%5C%5C%5C%5C%0A+%5Cfrac%7Ba%7D%7Bb%7D+%3D+%5Cfrac%7Bb_%7B1%7D%7D%7Ba_%7B1%7D%7D++++%3D++%5Cfrac%7Bb_%7B2%7D%7D%7Ba_%7B2%7D%7D+...+%3D+%5Cfrac%7Bb_%7Bn%7D%7D%7Ba_%7Bn%7D%7D+++++++++%5C%5C%0A+b_%7Bn%7D+%3D++ax++++++++++++++++++++++++++++%5C%5C%0A+a_%7Bn%7D+%3D+bx+%5C%5C+++%0A%0A+++++++++++++++++++++++++++++++++++++++++++++++++++%0A%0A++++++++)
То есть все пары
![a \in \ a ; bx\\ b \in b ; ax \\ x \in N](https://tex.z-dn.net/?f=++a+%5Cin+%5C+a+%3B+bx%5C%5C%0A+++++b+%5Cin+b+%3B+ax+%5C%5C%0A++++++++x+%5Cin+N)
(2sin38cos2+2cos52cos10)/4cos6cos4sin38=
=(2sin38cos2+2sin38cos10)/4cos6cos4sin38=
=2sin38(cos2+cos10)/cos6cos4sin38=(cos2+cos10)/2cos6cos4)=
=2cos6cos4/2cos6cos4=1
1) 0,03284925441 . 2) cos(п/3-a)=cos п/3 * cos a+sin п/3 * sin a
sin a=sqrt(1-(cos a)^2)
sin a=sqrt(1-(5/13)^2)=sqrt(1-(25/169))=sqrt(144/169)=12/13
cos(п/3-a)=1/2 * 5/13 + √3/2 * 12/13 =(5 + 12√3)/13 . больше не знаю )
Использованы правила действий с многочленами