1)8х²у+2ху²-4х²у²
2)х²+2х-3х-6=х²-х-6
3)(24х²у+18х³)/(-6х²)=-4у-3х
A)(5x-y)(5x+y)
б)(4n+m)(4n+m)
в)(6a-7)(6a+7)
г)(4-5х)(4+5х)
д)(3м-4н)(3м+4н)
е)(4p-9q)(4p+9q)
ж)(4б-7а)(4б-7а)
з)(0.1n-2m)(0.1+2m)
70%-23 800руб
30%- Х руб
70х=23 800*30
х=10 200
Ответ 10 200 руб
А1
, поэтому координаты точки ![\frac{7\pi}{3}](https://tex.z-dn.net/?f=%5Cfrac%7B7%5Cpi%7D%7B3%7D)
совпадают с координатами точки
, т.е. ![(\frac{1}{2};\frac{\sqrt{3}}{2})](https://tex.z-dn.net/?f=%28%5Cfrac%7B1%7D%7B2%7D%3B%5Cfrac%7B%5Csqrt%7B3%7D%7D%7B2%7D%29)
Ответ : 3)
А2 ![cosx=\frac{1}{\sqrt{2}}](https://tex.z-dn.net/?f=cosx%3D%5Cfrac%7B1%7D%7B%5Csqrt%7B2%7D%7D)
![cosx=\frac{\sqrt{2}}{2}](https://tex.z-dn.net/?f=cosx%3D%5Cfrac%7B%5Csqrt%7B2%7D%7D%7B2%7D)
на ![[0;\frac{\pi}{2}]](https://tex.z-dn.net/?f=%5B0%3B%5Cfrac%7B%5Cpi%7D%7B2%7D%5D)
Ответ: 2)
А3 ![t=\frac{71\pi}{4}=\frac{72\pi}{4}-\frac{\pi}{4}=18\pi-\frac{\pi}{4}](https://tex.z-dn.net/?f=t%3D%5Cfrac%7B71%5Cpi%7D%7B4%7D%3D%5Cfrac%7B72%5Cpi%7D%7B4%7D-%5Cfrac%7B%5Cpi%7D%7B4%7D%3D18%5Cpi-%5Cfrac%7B%5Cpi%7D%7B4%7D)
этот угол лежит в четвёртой четверти, там cos t >0
Ответ: 1)
А4 ![\frac{cos(\pi-t)+cos(\frac{\pi}{2}-t)}{sin(2\pi-t)-sin(\frac{3\pi}{2}-t)}}=\frac{-cost+sint}{-sint+cost}=](https://tex.z-dn.net/?f=%5Cfrac%7Bcos%28%5Cpi-t%29%2Bcos%28%5Cfrac%7B%5Cpi%7D%7B2%7D-t%29%7D%7Bsin%282%5Cpi-t%29-sin%28%5Cfrac%7B3%5Cpi%7D%7B2%7D-t%29%7D%7D%3D%5Cfrac%7B-cost%2Bsint%7D%7B-sint%2Bcost%7D%3D)
![=\frac{-(cost-sint)}{cost-sint}=-1](https://tex.z-dn.net/?f=%3D%5Cfrac%7B-%28cost-sint%29%7D%7Bcost-sint%7D%3D-1)
Ответ: 3)
А5 ![acos\frac{\pi}{2}+bsin\pi+tg\pi=a*0+b*0+c*0=0](https://tex.z-dn.net/?f=acos%5Cfrac%7B%5Cpi%7D%7B2%7D%2Bbsin%5Cpi%2Btg%5Cpi%3Da%2A0%2Bb%2A0%2Bc%2A0%3D0)
Ответ: 3)
А6 Ответ: 4) 225 град
![sin225=sin(180+45)=-cos45=-\frac{\sqrt{2}}{2}](https://tex.z-dn.net/?f=sin225%3Dsin%28180%2B45%29%3D-cos45%3D-%5Cfrac%7B%5Csqrt%7B2%7D%7D%7B2%7D)
![cos225=cos(180+45)=-cos45=-\frac{\sqrt{2}}{2}](https://tex.z-dn.net/?f=cos225%3Dcos%28180%2B45%29%3D-cos45%3D-%5Cfrac%7B%5Csqrt%7B2%7D%7D%7B2%7D)
B1 ![\frac{tgt}{sint}-\frac{sint}{ctgt}-cost=\frac{sint}{sint*cost}-\frac{sint*sint}{cost}-cost=](https://tex.z-dn.net/?f=%5Cfrac%7Btgt%7D%7Bsint%7D-%5Cfrac%7Bsint%7D%7Bctgt%7D-cost%3D%5Cfrac%7Bsint%7D%7Bsint%2Acost%7D-%5Cfrac%7Bsint%2Asint%7D%7Bcost%7D-cost%3D)
![=\frac{1}{cost}-\frac{sin^{2}t}{cost}-cost=\frac{1-sin^{2}t}{cost}-cost=\frac{cos^{2}t}{cost}-cost=](https://tex.z-dn.net/?f=%3D%5Cfrac%7B1%7D%7Bcost%7D-%5Cfrac%7Bsin%5E%7B2%7Dt%7D%7Bcost%7D-cost%3D%5Cfrac%7B1-sin%5E%7B2%7Dt%7D%7Bcost%7D-cost%3D%5Cfrac%7Bcos%5E%7B2%7Dt%7D%7Bcost%7D-cost%3D)
![=cost-cost=0](https://tex.z-dn.net/?f=%3Dcost-cost%3D0)