Докажите тождество:

1). (a^2+4) ^2-16a^2 = (a+2) ^2 (a-2) ^2

2). (4a+1) ^2 (4a-1) ^2 = (16a^2+1) ^2-64a^2

1) (a^2 + 4) ^2 - 16a^2 = (a + 2) ^2 * (a - 2) ^2

a^4 + 8a^2 + 16 - 16a^2 = (a^2 + 4a + 4) * (a^2 - 4a + 4)

a^ - 8a^2 + 16 = a^4 - 4a^3 + 4a^2 + 4a^3 - 16a^2 + 16a + 4a^2-16a - 16

a^4 - 8a^2 + 16 = a^ - 8a^2 + 16

a^ - 8a^2 + 16 - a^4 + 8a^2 - 16 = 0

(4a + 1) ^2 * (4a - 1) ^2 = (16a^2 + 1) ^2 - 64a^2

(16a^2 + 8a + 1) * (16a^2 - 8a + 1) = 256a^4 + 32a^2 1 - 64a^2

256a^4 - 128a^3 + 16a^2 + 128a^3 - 64a^2 + 8a + 16a^2 - 8a + 1 = 256a^4 - 32a^2 + 1

256a^4 - 32a^2 + 1 = 256a^4 - 32a^2 + 1

256a^4 - 32a^2 + 1 - 256a^4 + 32a^2 - 1 = 0