Question

4.) If a = 2, b = 0, c = 1, verify that:
(i) (a + b + c)2 = a + b2+ + 2ab +2bc +2ca
(ii) a + b + c-3abc = (a + b + c)(a + b2+e-ab-bc-ca).​

Answer 1

Answer:

i) For a=2,b=4,c=6 we have 

(a+b+c)2=(12)2=144 and

a2+b2+c2+2ab+2bc+2ca

=4+16+36+16+48+24

=144

ii) For a=5,b=−2,c=3 we have 

(a+b+c)2=(6)2=36 and

a2+b2+c2+2ab+2bc+2ca

=25+4+9−20−12+30

=36

iii) For a=−2,b=3,c=−4 we have 

(a+b+c)2=(−3)2=9 and

a2+b2+c2+2ab+2bc+2ca

=4+9+16−12−24+

Answer 2

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