Let a1, a2,… , an be fixed real numbers and define a function
f (x) = ( x − a1) ( x − a2)...( x − an) .
What is 
? For some 
compute 
.
Given function is f(x) = (x – a1) (x – a2) … (x – an)
:
⇒ 
=
= (a1 – a1) (a1 – a2) … (a1 – an) = 0
∴ 
:
⇒ 
=
= (a – a1) (a – a2) … (a – an)
∴ 
Ans. 
and 
31