What is the product of the the given equation?

Question

(x^4 + y^2)(x^4 - y^2)

Answer 1

Using the difference of two squares formula: (a+b)(a-b) = a^2 - b^2,

(x^4 + y^2)(x^4 - y^2) = (x^4)^2 - (y^2)^2 = x^8 - y^4