how do you factor r4-1296 completely?

Question

r^4-(3^2*2^4)?

I'm not sure how you do this but that was the answer I got

Answer 1

It is the difference of two perfect squares. The square root of 1296 is 3^1*2^2 = 36
(r^2 + 36)(r^2 - 36)
The second factor is also a difference of two perfect squares
(r^2+36)(r+6)(r-6)

Answer 2

This is the difference of perfect squares. When you have a perfect square, you take the power of the variable and see if it can be broken into two numbers that are exactly the same. Which in this case is yes, 2. You then find the square root of the number, which is 36. In order for there to be no middle term one of the numbers will need to be positive and one negative. Your answer is:
(r^2 - 36)(r^2 + 36). Then you see you have another perfect square so you have to continue. The final answer is
(r^2+ 36)(r-6)(r+6)

Answer 3

(r^2+36)(r+6)(r-6)