`f(x)=xe^(-x)` is decreasing in

f(x)=x.e^(-x) is decreasing in

f(x)=x*e^(-x) is decreasing in

f(x) = x^(x) is decreasing in the interval

f (x) = sec x is decreasing in

f(x)=x^(x) decreases in ……….

f(x)=(x^(2)-1)/(x) decreases in

Let f:[1,oo)->R and f(x)=x(int_1^xe^t/tdt)-e^x .Then (a) f(x) is an increasing function (b) lim_(x->oo)f(x)->oo (c) fprime(x) has a maxima at x=e (d) f(x) is a decreasing function

f'(x) = x^(2) - 5x + 4 then f(x) is decreasing in

f(x) =x/a+a/x(agt 0) is decreasing in