Question

Write the first five terms of the sequence whose nth terms are:

$straight a subscript straight n space equals space left parenthesis negative 1 right parenthesis to the power of straight n minus 1 end exponent space 5 to the power of straight n plus 1 end exponent$

Solution

Here, $straight a subscript straight n space equals space left parenthesis negative 1 right parenthesis to the power of straight n minus 1 end exponent 5 to the power of straight n plus 1 end exponent$
Putting n = 1, 2, 3, 4, 5, we get
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                       $straight a subscript 2 space equals space left parenthesis negative 1 right parenthesis to the power of 2 minus 1 end exponent 5 to the power of 2 plus 1 end exponent equals negative 5 cubed equals negative 125$
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