College Algebra › Symmetry
The above table refers to a function with domain
.
Is this function even, odd, or neither?
Neither
Even
Odd
A function is odd if and only if, for every
in its domain,
; it is even if and only if, for every
in its domain,
.
We see that and
. Therefore,
, so
is false for at least one
.
cannot be even.
For a function to be odd, since , it follows that
; since
is its own opposite,
must be 0. However,
;
cannot be odd.
The correct choice is neither.
Define .
Is this function even, odd, or neither?
Neither
Odd
Even
A function is odd if and only if, for all
,
; it is even if and only if, for all
,
. Therefore, to answer this question, determine
by substituting
for
, and compare it to both
and
.
, so
is not even.
, so
is not odd.
Consider the function .
Is an even function, an odd function, or neither?
Even
Odd
Neither
A function is even if, for each
in its domain,
.
It is odd if, for each in its domain,
.
Substitute for
in the definition:
Since ,
is an even function.
is a piecewise-defined function. Its definition is partially given below:
How can be defined for negative values of
so that
is an odd function?
cannot be made odd.
, by definition, is an odd function if, for all
in its domain,
, or, equivalently
One implication of this is that for to be odd, it must hold that
. If
, then, since
for nonnegative values, then, by substitution,
This condition is satisfied.
Now, if is negative,
is positive. it must hold that
,
so for all
,
the correct response.
is an even function;
.
True or false: It follows that .
False
True
A function is even if and only if, for all
in its domain,
. It follows that if
, then
.
No restriction is placed on any other value as a result of this information, so the answer is false.
Which of the following is true of the relation graphed above?
It is an odd function
It is an even function
It is a function, but it is neither even nor odd.
It is not a function
The relation graphed is a function, as it passes the vertical line test - no vertical line can pass through it more than once, as is demonstrated below:
Also, it can be seen to be symmetrical about the origin. Consequently, for each in the domain,
- the function is odd.
Which of the following is true of the relation graphed above?
It is an odd function
It is an even function
It is not a function
It is a function, but it is neither even nor odd.
The relation graphed is a function, as it passes the vertical line test - no vertical line can pass through it more than once, as is demonstrated below:
Also, it is seen to be symmetric about the origin. Consequently, for each in the domain,
- the function is odd.
is an even function. Let
.
Is an even function, an odd function, or neither?
Odd
Even
Neither
A function is even if, for each
in its domain,
.
It is odd if, for each in its domain,
.
Substitute for
in the definition of
:
Since is even,
, so
This makes an odd function.
Which of the following is symmetrical to across the origin?
Symmetry across the origin is symmetry across .
Determine the inverse of the function. Swap the x and y variables, and solve for y.
Subtract 3 on both sides.
Divide by negative two on both sides.
The answer is:
is a piecewise-defined function. Its definition is partially given below:
How can be defined for negative values of
so that
is an odd function?
, by definition, is an odd function if, for all
in its domain,
, or, equivalently
One implication of this is that for to be odd, it must hold that
. Since
is explicitly defined to be equal to 0 here, this condition is satisfied.
Now, if is negative,
is positive. it must hold that
,
so for all
This is the correct choice.