1) х^2 + 5х - 5х - 25 2)16х^2 + 36х^у - 36ху- 81у^2 4) 3m^2 - 6mt - 2t^2 5) 6p^2 + 30pq + 5q^2
Y=2cosx-4
y'=-2sinx
y''=2cosx
<span>d=1,2
</span>
a1=3,9
<span>a2=a1+1d
a3=a1+d2
a4=a1+3d
a5=a1+4d
a6=a1+5d
a7=a1+6d
a8 = a1 + 7d</span>
<span>8,7=12,3-3d
3d=12,3-8,7
d=1,2</span>
<span>
a1=12,3-6*1,2
a<span>1=3,9</span></span>
Решение .
1) Sin (-150) = sin (-90-60) = - cos(60)=-0,5
Ответ : Sina =-0,5.