First slide
Monotonicity
Question

If ϕ(x) is a polynomial function and ϕ(x)>ϕ(x)  x1 and ϕ(1)=0,then 

Moderate
Solution

Given ϕ(x)ϕ(x)>0 x1
or      exϕ(x)ϕ(x)>0 x1
or     ddxexϕ(x)>0 x1
Therefore,  exϕ(x)) is an increasing function x1.
Since ϕ(x) is a polynomial, 
      exϕ(x)>e1ϕ(1) or exϕ(x)>0 [ϕ(1)=0]
or    ϕ(x)>0

Get Instant Solutions
When in doubt download our app. Now available Google Play Store- Doubts App
Download Now
Doubts App