Question

X + Y is equal to 2 then X square + Y square is equal to 40 then find the value of x cube + y cube

Answer 1

First we will calculate xy by putting the value of x^2+y^2 in formula  (x+y)^2=x^2+y^2+2xy 4=40+2xy 2xy=-36 xy=-18 (x^3+y^3)=(x+y)(x^2-xy+y^2) =2*(x^2+y^2-xy) =2*(40-(-18)) 2*48 96 Answer is 96.