Question

. What is the value of a if -1 is a zero of the polynomial P(x)=ax3 - x2 + x + 4
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Answer 1

Step-by-step explanation:

Given that, -1 is a zero of p(x), therefore if we put x=1 in p(x) the resulting value should be equal to zero

putting x=(-1)

p(-1)=a(-1)³-(-1)²+(-1)+4=0

=> a×(-1) -(1)-1+4=0

=> -a -1-1+4=0

=> -a-2+4=0

=> -a+2=0

=> -a=-2

=> a=2

Verification

p(-1)= 2×(-1)³-(1)²-1+4

=> -2-1-1+4

=> -4+4=0