Question

If a2+b2+c2=16 and ab+bc+ca=10, find the value of a+b+c.

Answer 1

Hii there!!!

( a + b + c )^2 = a^2 + b^2 + c^2 + 2( ab + bc + ca )

=> ( a + b + c )^2 = 16 + 2×10

=> ( a + b + c )^2 = 36

=> a + b + c = Root 36 = 6

Hope it helps....

Answer 2

(a+b+c)^2-(2a+2b+2c)=a^2+b^2+c^2
(a+b+c)^2_2.10=16
a+b+c =6