Question

What is the value of Σ^3(4*(1/2)^I-1) I=1 ?

a.7/8
b.8
c.7/2
d.7

Answer 1

The answer is D.7 i hopes this helped

Answer 2

we are given

`\sum _(i=1)^3\:\left(4\left((1)/(2)\right)^(i-1)\right)`

we can expand it

`\sum _(i=1)^3\:\left(4\left((1)/(2)\right)^(i-1)\right)=4((1)/(2) )^(1-1)+4((1)/(2) )^(2-1)+4((1)/(2) )^(3-1)`

now, we can combine it

and we get

`\sum _(i=1)^3\:\left(4\left((1)/(2)\right)^(i-1)\right)=7`............Answer