funtions.. 2!!!

If f(x) and g(x) are two polynomial such that the polynomial h(x) = xf(x3) + x2g(x6) is divisible by x2+x+1, then
a. f(1) = g(1)
b. f(1) = g(1) ≠0
c. f(1) = -g(1) ≠0
d. none of these

1 Answers

1
Rohan Ghosh ·

as it is divisible by x2+x+1 we can write

xf(x3)+x2g(x6) = (x2+x+1)H(x)

where H(x) is another polynomial

as this is valid for all x

put x=ω

ωf(1)+ω2g(1)=0

put x=ω2

ω2f(1)+ω4g(1)=0

solving we get f(1)=g(1)=0

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