CA Foundation P3 · Chapter 2 · Question 3 of 9
If α and β are the roots of 3x² − 12x + 7 = 0, the value of α² + β² is:
Test yourself: pick an answer
Reveal answer & explanation
Correct answer: C) 34/3
Explanation
α + β = 12/3 = 4 and αβ = 7/3. Then α² + β² = (α + β)² − 2αβ = 16 − 14/3 = 34/3. Adding 2αβ instead of subtracting gives 62/3, and forgetting the factor 2 gives 41/3.
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