Find the exponential equation for the sequence: (0,3),(1,3.6),(2,4.32),(3,5.184)…

y = ?(?)^x

3 answers

To find the exponential equation for the given sequence \((0,3),(1,3.6),(2,4.32),(3,5.184)...\), we can assume the general form of the exponential equation is:

\[ y = a \cdot b^x \]

where \(a\) represents the initial value (the y-value when \(x=0\)) and \(b\) is the growth factor.

  1. Find the value of \(a\):

From the point \((0, 3)\): \[ y(0) = a \cdot b^0 = a = 3 \]

So we have: \[ a = 3 \]

  1. Find the growth factor \(b\):

Next, we can use the other points to determine \(b\). We can use the point \((1, 3.6)\): \[ y(1) = 3 \cdot b^1 = 3 \cdot b = 3.6 \] To solve for \(b\): \[ b = \frac{3.6}{3} = 1.2 \]

  1. Verification of \(b\):

To ensure that this value of \(b\) fits the other data points, we can calculate the next points using \(b = 1.2\).

For \(x=2\): \[ y(2) = 3 \cdot (1.2)^2 = 3 \cdot 1.44 = 4.32 \]

For \(x=3\): \[ y(3) = 3 \cdot (1.2)^3 = 3 \cdot 1.728 = 5.184 \]

Both match the given points in the sequence.

  1. Final equation:

Thus, the exponential equation for the sequence is:

\[ y = 3(1.2)^x \]

Find the common ratio for the sequence: (0,3),(1,3.6),(2,4.32),(3,5.184)…

To find the common ratio of the sequence given by the points \((0,3),(1,3.6),(2,4.32),(3,5.184)...\), we first note that this is not a geometric sequence but rather follows the form of an exponential function.

However, we can still find the ratio of successive terms to understand the growth factor of the sequence:

  1. Calculate the first common ratio between the first and second terms: \[ r_1 = \frac{y(1)}{y(0)} = \frac{3.6}{3} = 1.2 \]

  2. Calculate the second common ratio between the second and third terms: \[ r_2 = \frac{y(2)}{y(1)} = \frac{4.32}{3.6} = 1.2 \]

  3. Calculate the third common ratio between the third and fourth terms: \[ r_3 = \frac{y(3)}{y(2)} = \frac{5.184}{4.32} = 1.2 \]

Since each of these ratios is equal to \(1.2\), we can conclude that the common ratio for this sequence—reflecting the growth factor of the exponential function—is:

\[ \text{Common ratio} = 1.2 \]