(2/ 1)? =4
(4/2)? =4
(4/4)? = 1
( 1/4)? =X
X= 1/ 16
The second term divided by the square of the first term equals the third term.
The third term divided by the square of the second term equals the fourth term.
The fourth term divided by the square of the third term equals the fifth term.
The fifth term divided by the square of the fourth term equals the sixth term.
And so on: An+2=(An+ 1/An)?
There are many solutions to numerical reasoning, which can be thought from different dimensions, but the final answer is unique, so we are required not to solidify our thinking in the process of solving problems.
Sense of number: the so-called sense of number means that when we see a number, we should divergent our thinking and connect the attributes, characteristics and relevance of the number, that is, whether the number can be expressed in other forms. In order to cultivate your sensitivity, you must remember some special numbers, such as the square of 1 1-2 1, the cube of11,and the fifth power of 1-5. These multiples must be memorized and studied in the topic of numerical reasoning.
There are induction, formula, accumulation, multiplication, construction, reciprocal method, logarithm method, fixed point method and so on. A series of numbers arranged in a certain order is called a sequence, and each number in the sequence is called an item of this number.
If the relationship between the nth term an and n of series an can be expressed by a formula, this formula is called the general term formula of series. The general term of some series can be expressed by two or more formulas. There is also a series with general formula, such as a series composed of all prime numbers.
General formula:
If the relationship between the nth term an and n of the series {an} can be expressed by a formula, this formula is called the general term formula of the series. The general term of some series can be expressed by two or more formulas. There is also a series with general formula, such as a series composed of all prime numbers.