Divide x4−y4 by x2−y2.
Given (x4−y4)÷(x2−y2)
Since, we have a2−b2=(a−b)(a+b) .......(i)
Substitute a=x2 and b=y2 in equation(i), we get
(x2)2−(y2)2=(x2−y2)(x2+y2)
⇒(x4−y4)=(x2−y2)(x2+y2) ......(ii)
Now substitute equation(ii) in given expression.
(x4−y4)(x2−y2)=(x2−y2)(x2+y2)(x2−y2)
=x2+y2
Hence, the value of the given expression is =x2+y2