What is the sum of the squares of the roots of ?
Answer and explanation
Correct answer: D. 20
- Step 1: By Vieta, the sum of the roots is -2 and their product is -8.
- Step 2: x1^2 + x2^2 = (x1 + x2)^2 - 2 x1 x2 = 4 - (-16) = 20.
Answer
20.
Why not the others: 4 is the square of the sum; -12 adds 2p instead of subtracting it.
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