Answer:
Step-by-step explanation:
To Find :
Solution:
Recursive form :
Not all certain can defined in terms of recursive format .
In this form each term depends upon the preceding term .
It is formulated by starting term a and depends upon before term An-1.
It is like ladder structure
a2=a1+"step up".
Recursive formula as ,
F(n)=F(n-1)+d. ......... d is refered as the step up in the arithmetic sequence.
E.g. 10, 15, 20, 25..
step up is 5 units
hence for third term is ,
a3=a2+5=15+5=20.
hence proved by formula in recursive form.
Explicit Form:
This form will creates a sequence using n, and number term at that location.
i.e. It is formulated as the 1st and (one less than term number * common difference ).
F(n)=F(1)+d(n-1).
for same above example
f(3)=10+5(3-1)=10+5(2)=10+10=20.
hence proved same result using two different formula .
Arithmetic sequence problem:
consider as sequence :
-6, -1, 4, ?.
here common difference as
-1-(-6)=5 ,4-(-1)=5.
hence d=5.
F(4)=F(1)+d(4-1).
= -6+5(3)= -6 +15 =9.
The next term is 9 using explicit formula
now by recursive form
a4=a3+5=4+5=9
The 4th term is 9.
Hence in both forms term being same as "9".
Depending upon the sequence chose proper method to solve sequences.