I am not able to understand this step

#1

kindly help : the link to the image -> https://drive.google.com/file/d/16yyhzw797v-2_onC2oNeFwD8CXUaRDvE/view?usp=sharing

#2

please help with this part of the calculation of time complexity

#3

hello @av8055
focus on this part->
ss
the second term is in gp. so apply gp formula on the second term
gp formula = a * (1-r^n)/ (1-r)
here a=1 and r=1/2
and simplify it

#4 

2^(n-1) [  2*h  -  [1 - (1/2)^(n-1) ] / [1-1/2]    ]

2^(n-1) [  2*h  -  [1 - (1/2)^(n-1) ] / [1/2]    ]

2^(n-1) [  2*h  -  [1 - (1/2)^(n-1) ] / [1/2]    ]
2^(n-1) [  2*h  -  [2^(n-1) - 1 ] / [2^(n-1)/2]    ]
2^(n-1) [  2*h  -  [2^(n-1) - 1 ] / [2^(n-2) ]    ]
#5

why do we take the total terms to be (n-1) shouldn’t it be n-2??

#6

because the sereis starts with 0 power and goes till n-2.
so total n-1 terms are there

#7

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