Question

10. If x= (a +1/a)
and y = (a-1/a) then let's find the value of x4+y4-2x2y2
​

Answer 1

Step-by-step explanation:

Given, x=a+a1;y=a−a1

so, x2=a+a1+2;y2=a+a1−2

Ans, x2−y2=a+a1+2−a−a1+2=4

Now, (x2−y2)2=(4)2=16...(1)

Also, (x2−y2)=x4−y4−2x2y2...(2)

From (1) & (2), x4+y4−2x2y