Question

If x+y =5 and xy=1 then x^2+y^2 is​

Answer 1

Answer:

x2+y2=5⟹x2+y2+2xy=5+2xy⟹(x+y)2=5+2(1)=7(1)

x2+y2−2xy=5−2xy⟹(x−y)2=5−2(1)=3(2)

x4−2x2y2+y4=(x2−y2)2=[(x+y)(x−y)]2=(x−y)2(x+y)2

=(3)(7)=21using (1) and (2)

Answer 2

Answer:

hence , the value of x^2 +y^2 = 23