Let the sequence {an} be defined so that a1 = 1 and each succeeding term is found by multiplying the one before it by 4. Find the formula representing an, the nth term of the sequence.

Respuesta :

a₁ = 1 = 4⁰

a₂ = 4 =4¹

a₃ =4 x 4=4²

a₄ =4 x 4² =4³
...................
...................

a(n) = 4⁽ⁿ⁻¹⁾

Answer:

[tex]a_n=4^{n-1}[/tex]


Step-by-step explanation:


When each term is multiplied by a number to get the next term, it is a geometric sequence.

The general term (nth term) of a geometric sequence is given by the formula:

[tex]a_n=a_1*r^{n-1}[/tex]

Where [tex]a_1[/tex] is the first term and r is the common ratio (the number which is multiplied with a term to get the next term)

  • It is given that the first term, [tex]a_1[/tex], is 1
  • We also can figure out common ratio, r, to be 4 (since it is the number we multiply a term by, to get the next term)

Now plugging in these into the formula gives us:

[tex]a_n=a_1*r^{n-1}\\a_n=(1)*(4)^{n-1}\\a_n=4^{n-1}[/tex]