Verified answer

a) 2cos(x^3)+xlog2(x)

y ' =-2sin(x^3)*3x^2+log2(x)+x/(x*ln(2)=-6sin(x^3)*x^2+log2(x)+1/ln(2)

б) y=(x+4sin(x))/(2x^2+3)

    y ' =((1+4cos(x)*(2x^2+3)-(x+4sin(x)*4x))/(2x^2+3)^2=

        =(1+4cos(x))/(2x^3+3)-4x*(x+4sin(x)/(2x^2+3)^2

в) y=a^x*ln(x)=a^xln(x)*ln(x)+a^x*1/x=a^x*(ln(x))^2+a^x/x