Question

Factorize by using factor theorem: y^3-7y+6​

Answer 1

Let p(x) = y3 - 7y + 6 then,by trial and error method we find p(1) = 0

Therefore, (y - 1) is a factor of p(x).

By dividing p(x) by y-1 we get, y2+y - 6

=> y2 - 2y +3y -6

=> y(y - 2) +3(y - 2)

=> (y + 3)(y - 2)

Now, y3 - 7y + 6 can be written in the factorised form as (y - 1)(y + 3)(y - 2)

ANS: (y - 1)(y + 3)(y - 2)