Y=x²cosx-sinx x0=π
(x²cosx)'=(uv)' u=x² u'=2xdx v=cosx v'=-sinxdx
(uv)'=u'v+v'u=2xcox-x²sinx
y'=2xcosx-x²sinx-cosx
y'(π)=2πcos(π)-π²sin(π)-cosπ=-2π-0+1=1-2π
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y=√3sinx+cosπ/3-3/π*x²
y'=√3cosx+0-6/π*x
y'(π/6)=√3cosπ/6-6/π*π/6=√3*√3/2-1=1.5-1=0.5