a+b+c=5, ab + bc + ca = 12 হলে a2+b2+c2 = কত?

a+b+c=5, ab + bc + ca = 12 হলে a²+b²+c² = কত?

A 3

B 4

C 2

D 1

Solution

Correct Answer: Option D

a²+b²+c²=(a+b+c)²-2(ab+bc+ca)
=(5)²-2×12
= 25 -24

∴a²+b²+c²==1