Confused on fundamental multiple-choice problems?

1] x^2(5x^2+8)/x^2(3x^2-16)=(5x^2+8)/(3x^2-… , now replace x by 0 , 8/-16 =-1/2 . [2] f'=-3sin3x , f'(pi/9)=-3sin(3*pi/9)=-3sin(pi/3)=-3sqr… . [3] f(lnx)=(lnx)^2+2lnx , d/dx=2lnx*1/x+2/x=(2lnx+2)/x