Q.

limh0f(2h+2+h2)-f(2)f(h-h2+1)-f(1), given that f'(2)=6 and f'(1)=4                                  [2003]

1 does not exist  
2 is equal to -32  
3 is equal to 32  
4 is equal to 3  

Ans.

(4)

limh0f(2h+2+h2)-f(2)f(h-h2+1)-f(1)    [00-form]

=limh0f'(2h+2+h2)·(2+2h)f'(h-h2+1)·(1-2h)       (Using L'Hospital rule)

=f'(2)·2f'(1)·1=6×24×1=3