1a)f`=2*7x^6+4*1/2*x^(-1/2)=14x66+2/√x
б)f`=((x^2+1)`*(x^2-3)-(x^2+1)*(x^2-3)`)/(x^2-3)^2=(2x(x^2-3)-2x(x^2+1))/(x^2-3)^2=
=(2x^3-6x-2x^3-2x)/(x^2-3)^2=-8x/(x^2-3)^2
2)f`(x)=2*2x+3x^2=4x+x^2
f`(2)=8+4=12
f`(4)=16+16=32
f`(x-3)=4(x-3)+(x-3)^2=4x-12+x^2-6x+9=x^2-2x-3
3)f`(x)=4+4x; 4+4x≤0; 4x≤-4; x≤-1