Bytelearn - cat image with glassesAI tutor

Welcome to Bytelearn!

Let’s check out your problem:

Write an explicit formula that represents the sequence defined by the following recursive formula:

a_(1)=-7" and "a_(n)=a_(n-1)-5
Answer: 
a_(n)=

Write an explicit formula that represents the sequence defined by the following recursive formula:\newlinea1=7 and an=an15 a_{1}=-7 \text { and } a_{n}=a_{n-1}-5 \newlineAnswer: an= a_{n}=

Full solution

Q. Write an explicit formula that represents the sequence defined by the following recursive formula:\newlinea1=7 and an=an15 a_{1}=-7 \text { and } a_{n}=a_{n-1}-5 \newlineAnswer: an= a_{n}=
  1. Identify Pattern: The recursive formula given is an=an15a_{n}=a_{n-1}-5, with the initial condition a1=7a_{1}=-7. To find the explicit formula, we need to determine the pattern of the sequence by looking at the first few terms.
  2. Calculate First Few Terms: Let's calculate the first few terms using the recursive formula:\newlinea2=a15=75=12a_{2} = a_{1} - 5 = -7 - 5 = -12\newlinea3=a25=125=17a_{3} = a_{2} - 5 = -12 - 5 = -17\newlinea4=a35=175=22a_{4} = a_{3} - 5 = -17 - 5 = -22\newlineFrom these calculations, we can see that each term is 55 less than the previous term, which suggests that the sequence is arithmetic with a common difference of 5-5.
  3. Use Arithmetic Sequence Formula: The nnth term of an arithmetic sequence can be found using the formula an=a1+(n1)da_n = a_1 + (n - 1)d, where a1a_1 is the first term and dd is the common difference. In this case, a1=7a_1 = -7 and d=5d = -5.
  4. Substitute Values: Substituting the values of a1a_{1} and dd into the formula, we get:\newlinean=7+(n1)(5)a_{n} = -7 + (n - 1)(-5)\newlinean=75n+5a_{n} = -7 - 5n + 5\newlinean=5n2a_{n} = -5n - 2\newlineThis is the explicit formula for the given recursive sequence.

More problems from Convert between explicit and recursive formulas