(1)=(x^2+4)^2-(4x)^2,平方差公式=(x^2+4+4x)(x^2+4-4x)=(x+2)^2(x-2)^2
(2)=(x^2-9)^2=(x+3)^2(x-3)^2
(3)=(4x^2-1)(4x^2+1)=(2x+1)(2x-1)(4x^2+1)
(1)=(x^2+4)^2-(4x)^2,平方差公式=(x^2+4+4x)(x^2+4-4x)=(x+2)^2(x-2)^2
(2)=(x^2-9)^2=(x+3)^2(x-3)^2
(3)=(4x^2-1)(4x^2+1)=(2x+1)(2x-1)(4x^2+1)