1) 3х^2 + 8х - 3 = 3( Х - ( 1/3 ))( x + 3 ) = ( 3x - 1 )( x + 3 )
D = 64 + 36 = 100 = 10^2
X1 = ( - 8 + 10 ) : 6 = 1/3
X2 = ( - 8 - 10 ) : 6 = - 3
2) x^2 + 3x = x( x + 3 )
3) ( ( 3x - 1 )( x + 3 )) : ( x( x + 3 )) = ( 3x - 1 ) / x
А)y=x*tg³(x²-1)
y`=1*tg³(x²-1)+x*3tg²(x²-1)*1/cos²(x²-1) *2x=tg³(x²-1)+6xtg²(x²-1)/cos²(x²-1)
б)y=ln²(sin2x)
y`=2ln(sin2x)*1/sin2x *2cos2x=4cos2xln(sin2x)/sin2x=4ctg2x+ln(sin2x)
в)y=x²+(lnx-1)
y`=2x*(lnx-1)+x²*1/x=2x*(lnx-1)+x
a4+7d=a11
d=(30-2)/7=4
a3=a4-d=-2
a10=a11-d=26
a3+a10=24.....................