Identity - Additive
Identity
In basic arithmetic, the
additive identity is the number 0... Because
you can ADD 0 to
any number and that number keeps
its identity (it stays the same).
Example:
5
+ 0
=
5 |
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Identity -
Multiplicative Identity
In basic arithmetic, the
multiplicative identity is the number
1... Because
you can MULTIPLY 1 to
any number and that number keeps
its identity (it stays the same).
Example:
3
x 1
=
3 |
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Imaginary Number
The regular
numbers you usually work with are from the
Real Number
System. But, there is another kind of number - an
imaginary number. Imaginary numbers are in the form:
For more info on imaginary
numbers, check out my lessons on
complex numbers. |
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Improper Fraction
There's really nothing
"improper" about them and we use them in algebra
and higher math all the time. An improper
fraction is when the
numerator is greater than or equal to the
denominator.
For more info on improper fractions and how to
change them into mixed numbers, check out my
lesson on
improper fractions. |
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Inequality
An inequality is like
an
equation, but without the "equals" sign. Instead,
it has one of these signs:
Examples:
5 >
3
2x + 7 <
-9 |
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Infinite
An infinite list of
numbers goes on forever and ever and never stops.
Example: The whole
numbers: 0, 1, 2, 3, 4, ... |
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Infinity
Here is the official
symbol for infinity... It's a "figure eight" laying on
its side.
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Inscribed
Example: The
picture on the right... The
circle is said to be
inscribed in the
triangle
since the circle is
inside so that its
edge (circumference)
is just touching each
of the sides of the triangle. |
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Integer
An integer is one
member of
this set: {
... , -3,
-2,
-1,
0,
1,
2,
3,
4,
5, ...
} |
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Intersection
An intersection is
the
place where two
things cross. |
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Intersection of Sets
The intersection of
two sets is a set of elements that appears in both
sets.
Example:
A
= { 1,
2,
3,
a,
b,
c
}
B
= { 3,
4,
5,
b,
c,
f,
g
}
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Inverse - Additive
Inverse
The additive inverse
of a number, a, is the number,
-a, you
add to it to get
0
(the
additive identity).
a
+ (-a)
=
0
Examples: The
additive inverse of 8 is
-8 since
8 + (-8)
= 0
The
additive inverse of
-2 is 2
since -2
+ 2
=
0 |
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Inverse -
Multiplicative Inverse
The multiplicative
inverse of a number, a, is the number,
1/a, that you
multiply it to so you get
1 (the
multiplicative identity).
Example: The
multiplicative inverse of 5
is 1/5.
The
multiplicative inverse of
1/2 is 2. |
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Irrational Number
An irrational number
is a number whose decimal part goes on forever and ever
without repeating.
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