x2 cos π4sin x
We have,
ddx(x2 cosπ4×cosec x)
=cos π4 cosec x ddx(x2)+x2 cosec x ddx(cosπ4)+x2 cosπ4ddx(cosecx) [Using product rule]
=cosπ4 cosecx×2x+x2 cosec x×0+x2 cosπ4(−cosecx cotx). [∵ddx(cosπ4)=0]
=(2xsin x−x2 cosecxsin2x)cosπ4
∴cos π4(2xsin x−x2 cos xsin x)