31
If (ab + bc + ca) = 19 and (a + b + c) = 8, find the value of (a2 + b2 + c2).
- A24
- B25
- C26
- D27
Answer not set
Discussion 1
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CCommunity
? (a + b + c)2 = (a2 + b2 + c2) + 2(ab + bc + ca)
Substituting values,
⇒ (8)2 = (a2 + b2 + c2) + 2(19)
⇒ (a2 + b2 + c2) = 64 – 38
∴ (a2 + b2 + c2) = 26
Substituting values,
⇒ (8)2 = (a2 + b2 + c2) + 2(19)
⇒ (a2 + b2 + c2) = 64 – 38
∴ (a2 + b2 + c2) = 26