question_answer

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

(a)\[{{a}^{2}}+{{b}^{2}}\]

(b)\[{{a}^{2}}+ab+{{b}^{2}}\]

(c) \[{{a}^{2}}-{{b}^{2}}\]

Answer:

When a = 2, b = ? 2, then

(a) \[{{a}^{2}}+{{b}^{2}}={{\left( 2 \right)}^{2}}+{{\left( 2 \right)}^{2}}\]

= 4 + 4 = 8

(b) \[{{a}^{2}}+ab+{{b}^{2}}={{\left( 2 \right)}^{2}}+\left( 2 \right)\text{ }\left( 2 \right)+{{\left( 2 \right)}^{2}}\]

= 4 ? 4 + 4 = 4

(c) \[{{a}^{2}}{{b}^{2}}={{\left( 2 \right)}^{2}}{{\left( 2 \right)}^{2}}\]

= 4 ? 4 = 0