<span>=2cos2a*cosa/(2sina*cosa)+2sin2a*cosa/(1+2cos²a-1)=cos2a/sina+sin2a/cosa=(1-2sin²a)/sina+2sina*cosa/cosa=1/sina-2sina+2sina=1/sina=Coseca</span>
1. 2х^2-2ху-3ху+3у^2=2х^2-5ху+3у^2
2.3ху+3х^2-5у^2-5ху-3х^2=3ху-5у^2-5ху
3.3(у^2-2ху+х^2)+7х^2-7ху=3у^2-3ху+3х^2+7х^2-7ху=10у^2-10ху+10х^2=10(у^2-ху+х^2) могу ошибаться
4.-2(у^2-2ху+х^2)+4х^2-4ху=-2у^2+4ху-2х^2+4х^2-4ху=-2у^2+2х^2 могу ошибаться
5.16ху^2-4ха^2= 4х(4у^2-а^2)=4х(2у-а)(2у+а)
6.50ху^2-2ха^2=2х(25у^2-а^2)= 2х(5у-а)(5у+а)
везде могу ошибаться, все мы люди;)
3x^3 + 6x^2 = 12x + 243x^2 * (x + 2) = 12 * (x + 2)x^2 = 4x1 = + 2x2 = -2
1.1)=3(a+2b)
2)=4(3m-4n)
3)=5c(2k-3p)
4)=8a(x+1)
5)=5b(1-5c)
6)=7x(2x+1)
7)=n^5(n^5-1)
8)=m^6(1+m)
2.1)=266256-516*513=1548
2)0,343+0,7*0,51=0,7
3)0,0016-0,0088*1,2=-0,00896
3. 1)D=<span><span><span><span>(<span>−1</span>)^</span>2</span>−<span><span>4·1</span>·0</span></span>=<span>1−0</span></span>=<span>1
x1=-(-1)+1/2*1=2/2=1
x2=-(-1)-1/2*1=0/2=0
2)D=</span><span><span><span>15^2</span>−<span><span>4·1</span>·0</span></span>=<span>225−0</span></span>=<span>225=15
x1=-15+15/2*1=0/2=0
x2=-15-15/2*1=-30/2=-15
3)D=</span><span><span><span><span><span>(<span>−30</span>)^</span>2</span>−<span><span>4·5</span>·0</span></span>=<span>900−0</span></span>=900=30
x1=-(-30)+30/2*5=60/10=6
x2=-(-30)-30/2*5=0/10=0
4)</span><span><span><span><span>18^2</span>−<span><span>4·14</span>·0</span></span>=<span>324−0</span></span>=324=18
x1=-18+18/2*14=0/28=0
x2=-18-18/2*14=-36/28=-1,28</span>
2x+1<1
2x<0
x<0
D(y): 2x+1>0
2x>-1
x>-0.5
ответ (-0.5;0)