+0

# maths help

0
389
4

The first two terms of a geometric progression are 4 and  –6.  What is the 4th term?

Jun 2, 2017

#2
+99397
+2

This is a geometric progression

The common ratio is   -6/4  = -3/2

So....the nth term in the series can be fornd as

an =  a1 (r)(n - 1)    where  a1  =   4  and r  = -3/2

So......the 4th term is

a4  =  4(-3/2)(4 - 1)  =   4(-3/2)3    =  -27/2  =  -13.5

Jun 2, 2017
edited by CPhill  Jun 2, 2017

#1
+100025
0

The first two terms of a geometric progression are 4 and  –6.  What is the 4th term?

a=4 and d=-6-4=-10

\(T_n=a+(n-1)d\\ T_4=4+(4-1)*(-10)\\ T_4=4+(3)*(-10)\\ T_4=4+-30\\ T_4=-26\\ \)

.
Jun 2, 2017
#4
0

Thank You!! <3

Guest Jun 2, 2017
#2
+99397
+2

This is a geometric progression

The common ratio is   -6/4  = -3/2

So....the nth term in the series can be fornd as

an =  a1 (r)(n - 1)    where  a1  =   4  and r  = -3/2

So......the 4th term is

a4  =  4(-3/2)(4 - 1)  =   4(-3/2)3    =  -27/2  =  -13.5

CPhill Jun 2, 2017
edited by CPhill  Jun 2, 2017
#3
0

Thank You!!! <3

Guest Jun 2, 2017