Wed March 17, 2010 By:

plzzz ans this is it right or wrong????????????????//

1 Comments

7 years ago

so f'(x)=0 implies


(x-1)(x-2)>0


so


 either both factors must be +ve or both - ve.


if both are negative then


x-1<0


and


x-2<0


i.e.


x<1 and x<2   ie common  is  x<1


if both factors are positive, then,


x-1>0 and x-2>0


i.e. the common is x>2


so we see that function is increasing either if x<1 or if x>2


so  if func is increasing then x belongs to open interval minus infinity to 1 union 2 to infinity.


next,


f is decreasing when f'(x)<0


so the product(x-1)(x-2) must be negative


so either


x-1 >0 and (x-2)<0


or


x-1<0 and x-2>0


continuing like in the first case we get


func is decreasing when 1<x<2


 

Kasim Razak 2 2 days ago
Good. I like this video/chapter/test/question/greeting
Kasim Razak 3 2 days ago
Good. I like this video/chapter/test/question/greeting
Top Contributors this Month
#1
1793 Comments 1585 Likes
#2
430 Comments 434 Likes
#3
337 Comments 276 Likes
#4
674 Comments 569 Likes