tanxcosxSolutiongiven tanxcosx but tanx sinx cosx so tanxco

tan(-x)cos(-x)

Solution

given tan(-x)cos(-x)

but tan(x) = sinx /cosx

so tan(-x)cos(-x) = [ sin(-x)/cos(-x) ] . cos(-x)

now cos(-x)/cos(-x) =1

sow we will have only sin(-x) left

so  tan(-x)cos(-x) = sin(-x)

but sin(-x) = -sin(x)

so  tan(-x)cos(-x) = -sin(x)