Question

求 y=sin2x乘lnx的导数

Answer 1

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sin(2x) = 2sinxcosx

sin(a+b) = sinacosb+sinbcosa

cos(2x) = cos^2 x - sin^2 x

三角函数公式

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y' = lnx(sin2x)' + (sin2x)/x

= 2cos(2x)lnx + sin(2x)/x