Question

What is the value of the fourth term in a geometric sequence for which a1=10 and r=0.5?

Answer 1

\(\large { a_1\cdot r^{{\color{brown}{ n}}-1}\qquad \textit{so the 4th term is}
\begin{array}{ccllll}
term&value
\\\hline\\
{\color{brown}{ 1}}&a_1\cdot r^{{\color{brown}{ 1}}-1}\\
{\color{brown}{ 2}}&a_1\cdot r^{{\color{brown}{ 2}}-1}\\
{\color{brown}{ 3}}&a_1\cdot r^{{\color{brown}{ 3}}-1}\\
...&...
\end{array} }\)