Given: ……….(i)

= 

= 

= 

Now 

= 0

  or  or 

  or  or 

Now, for values of  close to  and to the left of . Also for values of  close to  and to the right of .

Therefore,  is the point of local maxima.

Now, for values of  close to 2 and to the left of . Also for values of  close to 2 and to the right of .

Therefore,  is the point of local minima.

Now as the values of  varies through  does not change its sign. Therefore,  is the point of inflexion.