Question

If (x+y)=6 and xy=4 then find the value of x^2+y^2 .

Answer 1

(x+y)²=x²+y²+2xy

36=x²+y²+2×4

36-8=x²+y²

x²+y²=28

Answer 2

(x+y)=6

S.B.S.

(x+y)^2=6^2

x^2+y^2+2xy=36

and we know xy=4

x^2+y^2+2*4=36

x^+y^2=28 ans