Question

if (x-a) is factor of f(x) then what is its remainder​

Answer 1

The remainder of f(x) is f(a)

Answer 2

Step-by-step explanation:

f(x)=(x−a)q(x)+r(x)

where, q(x) is the quotient when f(x) is divided by x−a and r(x) is the remainder.  

The Remainder Theorem says that we can restate the polynomial in terms of the divisor, and then evaluate the polynomial  

x=a

⇒f(a)=0×q(a)+r(a)

⇒f(a)=r(a)

Hence, the remainder is f(a).