This is a geometric sequence since there is a common ratio between each term. In this case, multiplying the previous term in the sequence by gives the next term. In other words, .
This is the form of a geometric sequence.
Substitute in the values of and .
Simplify the expression.
Apply the product rule to .
One to any power is one.
Combine and .
Substitute in the value of to find the th term.
Simplify the denominator.
Subtract from .
Raise to the power of .
Divide by .
Find the 5th Term 400 , 200 , 100