下列運(yùn)算正確的是( )
A.(ax2-bx+c)′=a(x2)′+b(-x)′
B.(sinx-2x2)′=(sinx)′-(2)′(x2)′
C.(cosxsinx)′=(sinx)′cosx+(cosx)′cos
D.[(3+x2)(2-x3)]′=2x(2-x3)+3x2(3+x2)
【答案】分析:利用函數(shù)的和差積商的導(dǎo)數(shù)運(yùn)算法則,逐個(gè)判斷即可.
解答:解:∵(ax2-bx+c)′=a(x2)′+b(-x)′+c′=a(x2)′+b(-x)′,故A正確;
(sinx-2x2)′=(sinx)′-(2x2)′=(sinx)′-2(x2)′,故B錯(cuò)誤;
(cosxsinx)′=(sinx)′cosx+(cosx)′sinx≠(sinx)′cosx+(cosx)′cosx,故C錯(cuò)誤;
[(3+x2)(2-x3)]′=2x(2-x3)-3x2(3+x2)≠2x(2-x3)+3x2(3+x2),故D錯(cuò)誤.
故選A.
點(diǎn)評(píng):本題考查導(dǎo)數(shù)的運(yùn)算法則,著重考查導(dǎo)數(shù)的加法與減法法則,導(dǎo)數(shù)的乘法與除法法則的靈活運(yùn)用,屬于中檔題.