sathee Ask SATHEE

Welcome to SATHEE !
Select from 'Menu' to explore our services, or ask SATHEE to get started. Let's embark on this journey of growth together! 🌐📚🚀🎓

I'm relatively new and can sometimes make mistakes.
If you notice any error, such as an incorrect solution, please use the thumbs down icon to aid my learning.
To begin your journey now, click on

Please select your preferred language

JEE PYQ: Binomial Theorem Question 42

Question 42 - 2019 (12 Apr Shift 1)

The coefficient of $x^{18}$ in the product $(1+x)(1-x)^{10}(1+x+x^2)^9$ is:

(1) 84 (2) $-126$ (3) $-84$ (4) 126

Show Answer

Answer: (1)

Solution

Simplifies to $(1-x^3)^9(1-x)$. Coefficient of $x^{18}$: ${}^9C_6 = 84$.


Learning Progress: Step 42 of 55 in this series