if lim f(x)= infinity= lim g(x) x->infinity x->infinty and lim f'(x)/g'(x)=infinity x-> infinity then lim f(x)/g(x)=inifity x-> inifinity The above fact is what im trying to prove. From my notes, i see the following: For m>0, choose k>0, such that if x> k* and g(x),f(x)>0, then f'(x)/g'(x)> m(4/3). this is actually where i get lost (so early into the process). can someone explain to me where exactly the prof is headed to with this info? also, is k a functional value through m? if so...how do i choose such k?