Question

If a = 2, b = – 2, find the value of: (i) a2+b2 (ii) a2+ab+b2(iii) a2–b2

Answer 1

(i) a2+b2 = (2)2+(-2)2 = 4+4=8 [putting a=2,b=-2]
(ii) a2+ab+b2 = (2)2+(2)(-2)+(-2)2 = 4-4+4=4 [putting a=2,b=-2]
(iii)a2–b2 = (2)2-(-2)2 = 4-4=0 [putting a=2,b=-2]