I Forgot The Formula - No Worry

subscribe to INVBAT.COM
Formula and Calculator as a Service
by Apolinario (Sam) Ortega

INVBAT.COM is helping students, teachers, and employees to create their own customized calculator website that works with their smartphone, tablet, laptop or desktop computer. Each calculator is $1.00 + website creation fee from $2 to $7.

Find first term in a geometric series

Instruction on how to use the calculator

Step 1. Enter 2 in box n₂ Why? It is the second number in geometric series.

Step 2. Enter 0.3 decimal equivalent of 3/10 the recorded value for second number

Step 3. Enter 6 in box n₆ Why? It is the six number in geometric series.

Step 4. Enter 1.51875 decimal equivalent of 243/160 the recorded value for the sixth number.

Then select the Solve button

Step 5. The answer is letter a = the first term of geometric series

Step 6. Now you can predict the last number at any position of the geometric series. How ? Enter any integer number in box n _nth to compute the expected value of the Last term, L nth term
For example n nth = 9
L nth = 5.1258

Step 7. Total number of geometric series up to the last number term or last position is calculated automatically.

a = r = n2 = L2 = a = Answer, first term

nnth = Lnth = Answer n6 = L6 = r =

The Graph of Geometric Function y = a r ^n-1

Notice the equation is similar to the Last Term equation L_n = a r ^n-1
Here a = first term of the series = 0.20 ;
r = geometric ratio = 1.5
And n = number of series is represented by the x-axis
While L = last term value is represented by the y-axis.