Question

Find the 4th term of the expansion of (a - sqrt(2)) ^ 8

Answer 1

Answer:

Applying the binomial theorem

${\displaystyle (x+a)^{n}=\sum _{k=0}^{n}{n \choose k}x^{n-k}a^{k}}$

Here we have x = -$\sqrt{2}$, n = 8,

=> 4th term (k = 3) would be:

${8 \choose 3}x^{8-3}a^{3}} = {8 \choose 3}(-\sqrt{2})^{5}a^{3}} = -224a^{3}\sqrt{2}$

Hope this helps!

:)

Answer 2

Answer:

A

Step-by-step explanation: