F(x)=-x^2+5x f’(x)

Question

F(x)=-x^2+5x f’(x)<0

Answer 1

2,5\\\\x\in(2,5;+\infty)" alt="f'(x)=(-x^2+5x)'=-2x+5\\\\f'(x)<0\\\\-2x+5<0\\\\-2x<-5\ /:(-2)\\\\x>2,5\\\\x\in(2,5;+\infty)" align="absmiddle" class="latex-formula">