2021 RI Promo Q5
(i)
Using standard series from the List of Formulae (MF26), expand $\frac{\cos 3x}{4-x}$ as far as the term in ${{x}^{3}}$. Give the coefficients as exact fractions in their simplest form.
[4]
(ii)
It is given that the third and fourth terms found in part (i) are equal to the third and fourth terms in the series expansion of ${{\left( a+bx \right)}^{5}}$, in ascending powers of $x$ respectively. Find the values of the constants $a$ and $b$.
[4]
Suggested Handwritten and Video Solutions
Share with your friends!
WhatsApp
Telegram
Facebook