X+Y+Z=1 and x3+y3+z3=4 then
?
(a)0
(b)1
(c)-3
(d)-2
Sol:
Put x = 0
y + z = 1, y³ + z³ = 4
(y + z)³ = 1
y³ + z³ + 3yz(y + z) = 1
4 + 3yz = 1
yz = -1
ATQ
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