Prove $or$ give a counterexample:

$(a)Iffis$ a linear function with positive slope, $fis$ increasing $onR.$

$(b)Iff$ and $g$ are decreasing functions $onan$ interval I and $f$@$gis$ defined $on$

I, then $f$@$gis$ decreasing $on$ I.

$(c)Iff$ and $g$ are decreasing functions $onan$ interval I and $f$@$gis$ defined $on$

I, then $f$@$gis$ increasing $on$ I.

$(d)If$ Dom$(f)=R$ and $fis$ increasing $on$ the intervals $-2,-1$ and $1,2,$

then $fis$ increasing $on-2,2.$

$(e)Iffis$ decreasing $on(-,0)$ and decreasing $on[0,),$ then $fis$

decreasing $onR.$

SOLVE part $bandc$ please. Thank you!