If (x+1) and (x-1) are factors of mx³ +x² - 2x +n find the value of m and n
Let, f(x)= mx3+x2−2x+n
Since (x+1) is a factor of f(x),
then f(−1)=0
⇒ −m+1+2+n=0
⇒ m−n=3........(1)
Since (x−1) is a factor of f(x),
then f(1)=0
⇒ m+1−2+n=0
⇒ m+n=1.........(2)
Solving from (1) and (2) we get m=2 and n=(−1)