JAMB - Mathematics (1989 - No. 16)
Solve for a positive number x such that \(2^{(x^3 - x^2 - 2x)} = 1\)
4
3
2
1
Explication
\(2^{(x^3 - x^2 - 2x)} = 1\)
\(x^3 - x^2 - 2x = 0\)
\(x(x^2 - x - 2) = 0\)
\(x^2 - x - 2 = 0\)
\((x + 1)(x - 2) = 0\)
x = 2 is the positive answer.