If a = 2, b = - 2, find the value of :

(i) a2 + b2


(ii) a2 + ab + b2


(iii) a2 - b2


(i) a2 + b2


Put a = 2 and b = -2


=(2)2 + (-2)2


=4 + 4


=8


(ii) a2 + ab + b2


Put a = 2 and b = -2


= (2)2 + 2(-2) + (-2)2


= 4 - 4 + 4


= 4


(iii)a2 (- b2


=Put a = 2 and b = -2


=(2)2 - (-2)2


= 4 - 4


= 0


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