Find an explicit formula for the geometric sequnce a1=15 and a3=135
Same thing as last time. Pull out 15 from both - a1 = 1, a3 = 9.
Ask: What can I multiply 1 by twice to get 9?
\(1 * x * x = 9\)
\(9 = x^2, x = 3\)
Okay so if a geometric equation is of form:
Then a = 15 (what we pulled out to make the problem easier to solve) and b = 3
\(y = 15(3^x)\)