If a,b,c are real numbers such that a + b + c = 0 and a2 + b2 + c2 = 1

1.	If a,b,c are real numbers such that a + b + c = 0 and a2 + b2 + c2 = 1, then (3a + 5b – 8c)2 + (–8a + 3b + 5c)2 + (5a – 8b + 3c)2 is equal to (A) 49 (B) 98 (C) 147 (D) 294
Answer» Correct Option :- (C) 147 Explanation :- Expanding are get 98 (a² + b² + c² ) – 98 (ab + bc + ca) = 98 – 98 (-1/2) = 147

If a,b,c are real numbers such that a + b + c = 0 and a2 + b2 + c2 = 1, then (3a + 5b – 8c)2 + (–8a + 3b + 5c)2 + (5a – 8b + 3c)2 is equal to (A) 49 (B) 98 (C) 147 (D) 294

Answer»

Correct Option :- (C) 147

Explanation :-

Expanding are get 98 (a² + b² + c² ) – 98 (ab + bc + ca) = 98 – 98 (-1/2) = 147

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If a,b,c are real numbers such that a + b + c = 0 and a2 + b2 + c2 = 1, then (3a + 5b – 8c)2 + (–8a + 3b + 5c)2 + (5a – 8b + 3c)2 is equal to (A) 49 (B) 98 (C) 147 (D) 294

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