Engineering Board Exam Reviewer · Polynomials: Remainder and Factor Theorems · medium
Find all roots of x3-3x2-4x+12=0.
- x=-3, 2, -2
- x=3, 4, -4
- x=3, 2, -2
- x=1, 2, -2
Answer
C. x=3, 2, -2
Solution
Group: x2(x-3)-4(x-3)=(x-3)(x2-4)=(x-3)(x-2)(x+2). The roots are 3,2,-2.
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