a4+4এর উৎপাদক কি কি?
A
(a2+2a+2)(a2-2a-2)
B
(a2+2a+2)(a2-2a+2)
C
(a2-2a+2)(a2+2a-2)
D
(a2-2a-2)(a2-2a+2)
Correct Answer: (a2+2a+2)(a2-2a+2)
a4 + 4 = (a2)2 + 22 = (a2 + 2)2 - 2.(a2).2 [a^2 + b^2 = (a + b)2 - 2ab] = (a2 + 2)2 - (2a)2 = (a2 + 2a + 2) (a2 - 2a + 2) [a2 - b2 = (a + b)(a - b)]