Which positive number is its own reciprocal? Which number has no reciprocal?
462144
1 is it's own reciprocal.  0 has no reciprocal because it is impossible to divide by 0.
406488
If the number in front of x^2 is positive it opens up.\nIf it is negative it opens down.
1032037
it is any number smaller then 4, for example 3.99999 or 2, or 0.00001, BUT NOT zero itself!!! (0=0, and not 0<0)\n\nSo x<4 is WRONG, the answer is: \nx<4 AND x is not equal to 0\nBUT x CANNOT be a negative number either, as -1(-1-4)=5!!\n\nSo the final answer is: \nx<4 and x>0 --- any figure will match your condition\n\nThanks for the math!
885957
You have probably figured out that no number will make this statement true. But don't forget about zero. \nYou will also find problems where even zero does not work. In those cases, "no solution" is the correct answer.
984348
This can't be answered either "true" or "false". Integers comprise the set of whole numbers (1,2,3,...) A positive integer and a negative integer will have a sum of zero if their absolute values are identical.(Absolute value is defined as the difference between a quantity and zero.So+1 and-1 have identical absolute values and their sum is zero, but +1 and -2 do not have identical absolute values, so their sum is not zero{it is, in fact,-1}).
234792
There are COUNTING NUMBERS: 1,2,3,.... These are"closed" for addition and multiplication. I.e. you only get a counting number when you add or multiply them.\n\nBut if we try to subtract them we get 0 and negative numbers which with the counting numbers make the INTEGERS.\n(... -2,-1,0,1,2,...)\n\nBut if we try dividing the integers we get rational numbers of the form a/b, like 33/47 or 34/17. (Integers are considered to be I/1).  When expressed in decimal form they either end in zeros or have a repeating pattern in the decimal (1/11 = 0.090909...)\n\nBut if we start taking roots we get numbers that cannot be expressed as a rational number.  These are IRRATIONAL NUMBERS.  Their decimal form has no repeating pattern - it's random digits. The square root of 2 or the cube root of 5 for example.\n\nThe rational and irrational numbers together make up the REAL numbers which account for all the points on the number line.\n\nThere are other ways to split the real numbers - algebraic (solutions to algebraic equations with real coefficients) or transcendental - those that are not the solution to any algebraic equation - Pi or e.\n\nThe next one that you didn't ask about is "imaginary" numbers.  The even root of a negative number.  They're not really imaginary but are very useful in electromagnetic theory for instance.  (The square root of (-1) really just means "1 at an angle of 90 degrees", Juat as -1 can be thought of as "1 at an angle of 180 degrees")
307994
The square root of negative 1 is the number, which multiplied by itself, gives negative 1.  Any real positive number when multiplied by itself gives a positive number.  Any real negative number when multiplied by itself gives a positive number.  Therefore no real number can be the square root of negative 1.\n\nHowever, it is useful to create a system of mathematics where negative one has a square root.  To do this we think of all the real numbers as belonging to a line.  We create another line, perpendicular to this line, and intersecting at zero.  We call this line the imaginary axis.  Then we invent rules for multiplying points in the plane defined by the real axis and the imaginary axis.  The way mathematicians have defined these things, the unit 1 on the positive imaginary axis when multiplied by itself is equal to negative 1.
1032089
discovery of the number 0?
595633
When you are dividing by something you are trying to find out how many of a certain amount (say, 3) is in another amount (say, 12). The result for my example, is of course 4, since 3 goes into the number 12 four times.\n\nNow the number 0 is nothing, literally. So if you're dividing into, say 12, you're wondering how much nothing is in 12. That's just not possible, because 12 is all "something".\n\nI hope that's clear enough...I tried.\n\nEdit: The guy above me is wrong.
901198
answer is 3s. any no. multiply by 1 is the no. itself.
1043253
A negative number may be an integer, but not a whole number.\n\nWhole numbers are "counting numbers" starting with zero: 0, 1, 2, 3, 4, . . .\nIntegers are everything without a decimal point: . . . -3, -2, -1, 0, 1, 2, 3, . . .\n1934234 is a whole number and an integer\n-36 is an integer, but not a whole number\n27.5 and -3.12 are neither whole numbers nor integers
1051417
Hi:\n\nRead the question by dreamchost1205 about the number pi and read iroc70 's answer it should explain thing very well.\n\nGood luck and best wishes to you
29898
Well it depends on what you want to define as a "number". Since you have already included imaginary and complex numbers, I might suggest you look at Hamilton's quaternions, which are noncommutative, and the nonassociative Cayley numbers, as well as Cantor's transfinite numbers. \n\nOf course, if we follow Leopold Kronecker, we might ignore everything except the integers:\n\n"God created the integers," wrote mathematician Leopold Kronecker, "All the rest is the work of Man."
711526
well, an integer is a whole number (postive or negative) or zero.\nsuch as 37463, or -2, or 0.
438101
Yes, in order to get a negative number after a positive number of multiplications or divisions, you must have the imaginary root of -1, or i. So if A x A x A x A equals a negative number, than A must be a real number with i.  In this case, it's  2 to the fourth power, or 16, and since it's -2, therefore it must be 16i.
493159
It does not have a real number value and is therefore defined as "i". i is an 'imaginary number'. The concept is a little too involved for me to be able to supply a complete answer describing imaginay numbers though. Hope that helps.
102547
A begining and no ending: Positive Integers\nAn ending and no begining: Negative Integers