Question

If a+b = 10 and ab=21, find the value of a 2 + b 2 .

Answer 1

A/Q (a+b)^2= a^2+b^2+2 ab
10*10=a^2+b^2+2*21
100 = a^2+b^2+42
100-42=a^2+b^2
58 = a^2+b^2 ans...