Question

(X^2-y^2/x^2+y^2)+(x^2+y^2/x^2-y^2)=√2, then x^8-y^8/x^8+y^8

Answer 1

If x and y are positive and x2y2=100, then for which of the following is the value of x+y greatest?

A. x=10
B. x=9
C. x=8
D. x=7
E. x=6x2y2100 --> xy22xy100 --> xy21002xy --> xy1002xy.We need to maximize xy, thus we need to maximize 1002xy. To maximize 1002xy we need to maximize xy.Now, for given sum of two numbers, their product is maximized when they are equal, hence from x2y2100 we'll have that x2y2 (or which is the same xy) is maximized when x2y2.In this case x2x2100 --> x507.Answer: D.

Answer 2

D....... .B JIGS AT GUCCI MANE