In the expansion of 1 + x + x 3 + x 4 10 , the coefficient of x 4 is

Question

In the expansion of 1 + x + x 3 + x 4 10 , the coefficient of x 4 is, 235, 310, 285, 325

MARKS App · Accepted Answer

1 + x + x 3 + x 4 10 = 1 + x 1 + x 3 10 = 1 + x 10 1 + x 3 10 = 1 + C 1 10 x + C 2 10 x 2 + C 3 10 x 3 + C 4 10 x 4 … × 1 + C 1 10 x 3 + C 2 10 x 6 + … . ∴ Coefficient of x 4 = C 1 10 C 1 10 + C 4 10 = 100 + 210 = 310

Search any question & find its solution

Looking for more such questions to practice?