Rinkoo Gupta
Last Activity: 11 Years ago
y=(cosx)2+sinx
dy/dx=2cosx(-sinx)+cosx
put dy/dx=0
-2sinxcosx+cosx=0
cosx[1-2sinnx]=0
=> either cosx=0 or 1-2sinx=0
=>x=pie/e or sinx=1/2
=>x=pie/2 or pie/6
d2y/dx2=-2cos2x-sinx
d2y/dx2 at xpie/2=-2cospie-sinpie/2=2-1
=1>0
so function is minima at x=pie/2
d2y/dx2 at pie/6=-2cospie/3-sinpie/6
=-3/2 <0
so function is maxima at pie/6
Thanks & Regards
Rinkoo Gupta
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