basic maths II help with homework :p

[Demio]

IF X + Y =2 AND XY=1
THEN FIND X^4 + Y^4 = ?

sorry for the stupid question ...I'm not good at math

 

[Deleted member 4993]

IF X + Y =2 AND XY=1
THEN FIND X^4 + Y^4 = ?

sorry for the stupid question ...I'm not good at math

e

Hint:

Calculate x² + y² using (x + y)² = x² + y² + 2xy

Then square again.....

 

[Demio]

e

Hint:

Calculate x² + y² using (x + y)² = x² + y² + 2xy

Then square again.....

Thank you ...I thought of it ..maybe I should have actually tried it

 

[CatMath]

(x^2+y^2)^2 is not equal to x^4+y^4, therefore you are incorrect.
given X+Y = 2 and XY = 1, the only fitting number pair is (1;1)
Therefore X^4+Y^4 = 1^4 + 1^4 = 2

 

[CatMath]

(x²+y²)² is not equal to x⁴ + y⁴

​Given XY=1 and X+Y=2 the only possible(real) number pair is (1;1)
Therefore x⁴ + y⁴ = 2

My answer is super late though

 

[fansonnorthgate]

Anyone assumes the pair is 1,1, she'd prove that first