Bytelearn - cat image with glassesAI tutor

Welcome to Bytelearn!

Let’s check out your problem:

Find an explicit formula for the geometric sequence

(1)/(2),-4,32,-256,dots
Note: the first term should be 
a(1).

a(n)=

Find an explicit formula for the geometric sequence\newline12,4,32,256,\frac{1}{2}, -4, 32, -256, \dots\newlineNote: the first term should be a(1)a(1).\newlinea(n)=a(n)=

Full solution

Q. Find an explicit formula for the geometric sequence\newline12,4,32,256,\frac{1}{2}, -4, 32, -256, \dots\newlineNote: the first term should be a(1)a(1).\newlinea(n)=a(n)=
  1. Sequence Type: We have the sequence: (12),4,32,256,(\frac{1}{2}), -4, 32, -256, \ldots\newline\newlineIs the given sequence geometric or arithmetic?\newline\newline(12),4,32,256,(\frac{1}{2}), -4, 32, -256, \ldots\newline\newlineHere, each term is multiplied by a common ratio.\newline\newlineThe given sequence is geometric.
  2. Determining a1a_1 and rr: Determine the values of a1a_1 and rr of the sequence.\newlineFirst term: a1=12a_1 = \frac{1}{2}\newlineCommon ratio: r=412=8r = \frac{-4}{\frac{1}{2}} = -8
  3. Expression for an: Determine an expression to describe ana_n.
    Substitute 12\frac{1}{2} for a1a_1 and 8-8 for rr.
    an=a1r(n1)a_n = a_1 r^{(n - 1)}
    an=(12)(8)(n1)a_n = \left(\frac{1}{2}\right)(-8)^{(n-1)}

More problems from Write variable expressions for geometric sequences