Enrique A. answered • 06/05/19
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New to Wyzant
Computer Science PhD student with 10 years of teaching experience
a[0] = 100
a[n] = a[n-1] / -2
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a[n] = a[0] / (-2n)
Enrique A.
The first term of the sequence is 100. We denote this fact by a[0] = 100. The next term of the sequence is almost half the current term, except that is negative. Note that the sings of the sequence alternate (positive, negative, positive, negative, etc). So, if the current term is a[n-1], the next one is a[n] = a[n-1] / -2. Now, note that to obtain the formula for the nth term of the sequence as a function of the first term, we can multiply all the way down to the first term: a[n] = a[n-1] / -2 = (a[n-2]/-2)/-2 = ((a[n-3]/-2)/-2)/-2=...=a[0]/(-2)^n.
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06/07/19
Tori M.
Could you explain please? I'm a little confused.06/07/19