= (сos^2 a + cos a*(-cos a)) / (-ctg a) * (-ctg a) = 0
5х²-10ху+5у²=5(х²-2ху+у²)=5(х-у)²
<span>х(х+y)²-y(x-y)²+2y(x²+y²)</span>=x(x²+2xy+y²)-y(x²-2xy+y²)+2x²y+2y³=
=x³+2x²y+xy²-x²y+2xy²-y³+2x²y+2y³=x³+3x²y+3xy²+y³=(x+y)³
(x+y)³ при <span>х=2,5 , у=0,5
(2,5+0,5)³=3³=27</span>
X=0,
y = 7*0 - 3 = - 3
For x=1,
y = 7*1 - 3 = 4. и через точки черти прямую
При: x=1,1 y=-0,3
9p²-q²
14x/(x+3y)= 14*1,1) / (1,1+3(-0,3) =1,54 /(1,1-0,9)=1,54/0,2= 7,7
Xxxxxx
a) При: p=2,3 , q=-1,9
9p²-q²=3,3)²-(-1,9)²=3*59-3,61=15,87-3,61=12,26
b) При: p=3/14 , q=5/14
9p²-q² = 9*(3/14)²-(5/14)²=5*9/196 -25/196= 45/196-25/196=
=20/196=5/49