Question

If the sum of $q$terms of an A.P is given by $3q-3q^2$ and the $p^{th}$ term is $0$. Find the value of $p$.

Answer 1

$s_{p-1}=3(p-1)-3(p-1{)}^2$

$=3p-3-3p^2+6p-3$

$=-3p^2+9p-6$

$s_p=3p-3p^2$

$T_p=S_p-S_{p-1}$

$o=3p=3p^2+3p^2-a_{p+6}$

$o=-6_{p+6}$

$\Rightarrow p=1$