Question

the temperature at 12 noon was the temperature at 12 noon was 10 degree Celsius above zero if it decreases at the rate of 2 degree Celsius per hour until midnight at what time would the temperature be 8 degree Celsius below zero? what would be the temperature at midnight​

Answer 1

(a + b + c)2 = a2 + b2 + c2 + 2(ab + bc + ca)

⇒ (9)2 = a2 + b2 + c2 + 2 x 23

⇒ 81= a2 + b2 + c2 + 46

⇒  a2 + b2 + c2 = 81 – 46 = 35

∴ a2 + b2 + c2 = 35