Question #1f6de

1 Answer
Feb 21, 2017

a_4=a_3xx6 " "=" " 144xx6 " "=" " 864a4=a3×6 = 144×6 = 864

a_5=a_5xx6" "=" "864xx6" "=" "5184a5=a5×6 = 864×6 = 5184

a_6=a_5xx6" "=" "5184xx6" "=" " 31122a6=a5×6 = 5184×6 = 31122

Explanation:

Let the term count be ii
Let the ith term be a_iai

So we have:
i=1->a_i =a_1=4i=1ai=a1=4
i=2->a_i=a_2=24i=2ai=a2=24
i=3->a_i=a_3=144i=3ai=a3=144

The question states this is a geometric sequence.

Let the expression for the term be a_ir^nairn
Where rr is the common ratio and nn is some variant (function) of ii

color(brown)("Determine the value of "r)Determine the value of r

24/4= 6244=6

144/24=614424=6

Thus r=6r=6
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
color(brown)("Determine the next three terms")Determine the next three terms

The last known term is a_3=144a3=144

so we have:

a_4=a_3xx6 " "=" " 144xx6 " "=" " 864a4=a3×6 = 144×6 = 864

a_5=a_5xx6" "=" "864xx6" "=" "5184a5=a5×6 = 864×6 = 5184

a_6=a_5xx6" "=" "5184xx6" "=" " 31122a6=a5×6 = 5184×6 = 31122