If f(x) =x4-2x3+3x2-ax-b when divided by x-1, the remainder is 6, then find the value of a + b

f(x) = x⁴ -2x2 +3x2 -ax -b

Given f(x) is divided by (x-1), then remainder is 6


f (1) = 6


1⁴ - 2 (1)3 - 3 (1)2 - a (1) - b = 6


1 -2 +3 -a -b = 6


-a -b = 4


a + b = - 4


6