If a + b + c = 15 and ab + bc + ca = 22, then find the value of a2 + b2 + c2.
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 181.
(a + b + c)2 = a2 + b2 + c2 + 2(ab + bc + ca)
According to the given question,
⇒ 152 = a2 + b2 + c2 + 2(22)
⇒ 225 = a2 + b2 + c2 + 44
⇒ a2 + b2 + c2 = 225 - 44
⇒ a2 + b2 + c2 = 181