What is the sum of the squares of the roots of x^2 - 3x - 4 = 0?
Answer and explanation
Correct answer: A. 17
- Step 1: By Vieta, the sum of the roots is 3 and their product is -4.
- Step 2: x1^2 + x2^2 = (x1 + x2)^2 - 2 x1 x2 = 9 - (-8) = 17.
Answer
17.
Why not the others: 9 is the square of the sum; 1 adds 2p instead of subtracting it.
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