The third term of a geometric sequence is 144 and the sixth term is 486. What is the first term of the sequence?
+118608 The third term of a geometric sequence is 144 and the sixth term is 486. What is the first term of the sequence?
$$\\ar^2=144\qquad ar^5=486\\\\
\frac{ar^5}{ar^2}=486/144\\\\
r^3=3.375\\\\
r=1.5\\\\\\
a*1.5^2=144\\
a*2.25=144\\
a=64\\\\\\
check\\
64*1.5^5=486 \;\;:)$$
+118608 The third term of a geometric sequence is 144 and the sixth term is 486. What is the first term of the sequence?
$$\\ar^2=144\qquad ar^5=486\\\\
\frac{ar^5}{ar^2}=486/144\\\\
r^3=3.375\\\\
r=1.5\\\\\\
a*1.5^2=144\\
a*2.25=144\\
a=64\\\\\\
check\\
64*1.5^5=486 \;\;:)$$
