====== Ch 06: Sequences and Series ====== * If $\frac{1}{a}$, $\frac{1}{b}$ and $\frac{1}{c}$ are in $G.P$. Show that $r=\pm \sqrt{\frac{a}{c}}$ --- //BISE Gujranwala(2015),BISE Sargodha(2015), BISE Sargodha(2017),BISE Lahore(2017)// * With usual notation show that $AH=G^2$ ---// BISE Gujrawala(2015)// * Find $n$, so that $\frac{a^n+b^n}{a^{n-1}+b^{n-1}}$ maybe $A.M$ between $a$ and $b$. --- //BISE Gujrawala(2015)// * If $y=1+\frac{x}{2}+\frac{x^4}{4}+...$ Show that $x=2(\frac{y-1}{y})$ --- //BISE Gujrawala(2017)// * Find the $9th$ term of harmonic sequence $\frac{1}{3}, \frac{1}{5}, \frac{1}{7},...$ --- //BISE Gujrawala(2017)// * If $a=-2$, $b=-6$, find $A.G$ --- //BISE Gujrawala(2017)// * If $\frac{1}{a}$, $\frac{1}{b}$, $\frac{1}{c}$ are in $A.P$ then show that common difference is $\frac{a-c}{2ac}$ --- //BISE Sargodha(2015)// * If $15$ and $8$ are two A.Ms between $a$ and $b$, find $a$ and $b$. --- //BISE Sargodha(2015)// * If $S_2,S_3,S_5$ are the sum of $2n,3n,5n$ terms of $A.P$. Show that $S_5=5(S_3-S_2)$ --- //BISE Sargodha(2015), BISE Sargodha(2017)// * The sum of $9$ terms of an $A.P$. is $171$ and its eight term is $31$. Find series. --- //BISE Sargodha(2015)// * Find three $A.Ms$ between $3$ and $11$ --- //BISE Sargodha(2016)// * How many terms of $-7+(-5)+(-3)+...$ amount to $65$ --- //BISE Sargodha(2016),FBISC(2016)// * If $a=2i$, $b=4i$ show that $AH=G^2$ --- //BISE Sargodha(2016)// * If $y=\frac{2}{3}x+\frac{4}{9}x^2+\frac{8}{27}x^3+...$ and $0 {{tag>FSc FSc_Part1 Important_Questions_FSc_1}}