=a^4b²+a³b³+a³b³-4a²b^4-2a^4b²-12a²b^4=2a³b³-a^4b²-16a²b^4.
(знак a^4---a в 4 степени)
<span>22cos^2x+4(2sinxcosx)=7(cos^2x+sin^2x)
</span><span>22cos^2x+8sinxcosx=7cos^2x+7sin^2x
</span><span>15cos^2x+8sinxcosx-7sin^2=0 /:cos^2
</span><span>15+8tgx-7tg^2x=0
</span><span>tgx=t
</span><span>-7t^2+8t+15=0
</span><span>7t^2-8t-15=0
</span><span>D=64+420=484
</span><span>t=8(+-)22
</span>14<span>t1=2
</span><span>t2=1
</span><span>tgx=1 tgx=2
</span><span>x=arctg1+ПK x=arctg2+ПK</span>
(система)y=-33x+25,y=-16x-26;
Cost = 3/4 cos(t/2) = ((1 + cost)/2)^(1/2) = ((1 + 3/4)/2)^(1/2) = (7/8)^(1/2) = (7^(1/2))/(2*(2^(1/2))) sin(t/2) = (1 - cos^2(t/2))^(1/2) = (1 - 7/8)^(1/2) = 1/(8^(1/2)) = 1/(2*(2^(1/2))) tg(t/2) = sin(t/2)/cos(t/2) = (1/(2*(2^(1/2))))/((7^(1/2))/(2*(2^(1/2)))) = 1/(7^(1/2)) ctg(t/2) = 1/tg(t/2) = 7^(1/2)<span> </span>