20. The H. M. between 2 and 8 is
(1 marks )​

Answer as an improper fraction = 16/5

Answer as a mixed number = 3 & 1/5

Answer in decimal form = 3.2

All of those values represent the same thing, but written in a different way.

Explanation:

I'm assuming HM stands for Harmonic Mean in this case.

If so, then we apply the reciprocal operation to each value to get 1/2 and 1/8 (from 2 and 8 respectively).

Add up those fractions:

1/2 + 1/8 = 4/8 + 1/8 = 5/8

Now we'll divide n = 2 over that result. The n = 2 refers to the number of items in the original set.

n divide over (5/8) = 2*(8/5) = 16/5 which is the answer as an improper fraction

To convert to a mixed number, we can do the following:

16/5 = (15+1)/5

16/5 = 15/5 + 1/5

16/5 = 3 + 1/5

16/5 = 3 & 1/5

Or if you need the answer in decimal form, then using a calculator would get you 16/5 = 3.2

geometric series converge the common ratio r has magnitude less than one.

which is equivalent to

for the example we need

|2-x| < 1

-1 < 2-x   and 2-x < 1

x < 3 and x > 1

we can write that

answer: 1 < x < 3

1a. common ratio r=250/25=10 > 1     diverges

1b.   r=50/100=1/2 converges

when these converge they converge to

where a is the first term.

answer: 200

1c. r=-1   so it's not the case that |r| < 1.     diverges

2a. x is the common ratio so we converge when |x|< 1

2b.   r=-10x / -2 = 5x.

we converge when

|5x| < 1

|x| < 1/5

2c.   r=3-2x

-1 < 3-2x and 3-2x < 1

-4 < -2x and 2 < 2x

x < 2 and 1 < x

1 < x < 2

2d. [/tex] r=-48x^3/12 = 4x^3[/tex]

|4x^3| < 1

|x^3| < \frac 1 4

|x| < 4^{-1/3}