Evaluate
We know that-
Hence
= a6 + 6a5b + 15a4b2 + 20a3b3 + 15a2b4 + 6ab5 + b6
Thus, (a + b)6 = a6 + 6a5b + 15a4b2 + 20a3b3 + 15a2b4 + 6ab5 + b6
Replacing b with -b
(a +(-b))6 = a6 + 6a5(-b) + 15a4(-b)2 + 20a3(-b)3 + 15a2(-b)4 + 6a(-b)5 + (-b)6
(a - b)6 = a6 - 6a5b + 15a4b2 - 20a3b3 + 15a2b4 - 6ab5 + b6
Now,
(a + b)6 - (a - b)6
= (a6 + 6a5b + 15a4b2 + 20a3b3 + 15a2b4 + 6ab5 + b6)
- (a6 - 6a5b + 15a4b2 - 20a3b3 + 15a2b4 - 6ab5 + b6)
= 2(6a5b + 20a3b3 + 6ab5)
Putting a = √3 & b = √2, we get-
(√3 + √2)6 - (√3 - √2)6
= 2[6(√3)5(√2) + 20(√3)3(√2)3 + 6(√3)(√2)5]
= 2[6(9√3)(√2) + 20(3√3)(2√2) + 6(√3)(4√2)]
= 2[54√6 + 120√6 + 24√6]
= 2[198√6]
= 396√6