Example1. First term `a=1`, Common ratio `r=2`, Number of terms `n=10` Find `n^(th)` term (last term) and sum of the geometric progression
Solution: Here `a=1,r=2,n=10`
We know that, `a_n = a × r^(n-1)`
`a_10=1×2^(10 - 1)`
`=1×512`
`=512`
We know that, `S_n = a * (r^n - 1)/(r - 1)`
`:.S_10=1× (2^10 - 1)/(2 - 1)`
`=>S_10=1× (1024 - 1)/1`
`=>S_10=1×1023/1`
`=>S_10=1023`
Hence, `10^(th)` term of the given series is `512` and sum of first `10^(th)` term is `1023`
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