Question

Write a conjecture that best describes the pattern in each sequence . Then use your conjecture to find the n next item in the sequence . a 1,4,9,16,... b PERCENT HUMIDITY : 100\% , 93 % , 86\%

Answer 1

patternpatternGreat!

The patteren is 1, 4, 9, 16,...

All these numbers are square numbers, which means

1 * 1 = 1

2 * 2 = 4

3 * 3 = 9

4 * 4 = 16

That means

1st term = 1^2

2nd term = 2^2

3rd term = 3^2

4th term = 4^2

so

nth term = n^2

The conjecture is

`a_n=n^2`

The pattern is 100%, 93%, 86%, ...........

Since 93% - 100% = -7%

Since 86% - 93% = -7%

Then this pattern is decreases by 7%

So it is an arithmetic sequence

Its rule is:

`a_n=a+(n-1)d`

Where a is the first term

d is the constant difference

n is the position of the number

Since a = 100%

Since d = -7%

Let us substitute these values in the rule

`a_n=100+(n-1)(-7)`

Simplify it

an = 100% + (n)(-7%) + (-1)(-7%)

an = 100% + (-7n%) + (7%)

Add the like terms

an = (100% + 7%) - 7n%

an = 107% - 7n%

Let us check the rule

What is the 3rd term

n = 3

a3 = 107% - 7(3)%

a3 = 107% - 21%

a3 = 86% which is true