All SAT Math Resources
Example Questions
Example Question #13 : How To Find F(X)
If , then
,
Example Question #161 : How To Find F(X)
Define two functions as follows:
Evaluate .
By definition, .
First, evaluate by setting in the definition of :
, so evaluate similarly:
Example Question #162 : How To Find F(X)
Define , restricting the domain of the function to the interval .
Give the range of the function.
None of these
If , then, by way of the properties of inequality, we can multiply all expressions by 2:
then add 3 to all expressions:
Taking the square root of all expressions, we get
So
.
The correct range is .
Example Question #201 : Algebraic Functions
Define two functions as follows:
Evaluate:
None of these
By definition, .
First, evaluate by setting in the definition of :
, so evaluate similarly:
Example Question #33 : Algebraic Functions
The function is defined as . What is ?
24
56
18
36
-36
24
Substitute -1 for in the given function.
If you didn’t remember the negative sign, you will have calculated 36. If you remembered the negative sign at the very last step, you will have calculated -36; however, if you did not remember that is 1, then you will have calculated 18.
Example Question #34 : Algebraic Functions
If the function is created by shifting up four units and then reflecting it across the x-axis, which of the following represents in terms of ?
We can take each of the listed transformations of one at a time. If is to be shifted up by four units, increase every value of by 4.
Next, take this equation and reflect it across the x-axis. If we reflect a function across the x-axis, then all of its values will be multiplied by negative one. So, can be written in the following way:
Lastly, distribute the negative sign to arrive at the final answer.
Example Question #1 : How To Use The Quadratic Function
If x2 + 2x - 1 = 7, which answers for x are correct?
x = -4, x = 2
x = -3, x = 4
x = -5, x = 1
x = 8, x = 0
x = -4, x = -2
x = -4, x = 2
x2 + 2x - 1 = 7
x2 + 2x - 8 = 0
(x + 4) (x - 2) = 0
x = -4, x = 2
Example Question #2 : How To Use The Quadratic Function
Which of the following quadratic equations has a vertex located at ?
The vertex form of a parabola is given by the equation:
, where the point is the vertex, and is a constant.
We are told that the vertex must occur at , so let's plug this information into the vertex form of the equation. will be 3, and will be 4.
Let's now expand by using the FOIL method, which requires us to multiply the first, inner, outer, and last terms together before adding them all together.
We can replace with .
Next, distribute the .
Notice that in all of our answer choices, the first term is . If we let , then we would have in our equation. Let's see what happens when we substitute for .
Example Question #1 : How To Use The Quadratic Function
If , which two values of are correct?
First, we set the quadratic function equal to :
Reduce the function to its two component factors:
Therefore, since either or ,
Example Question #2 : How To Use The Quadratic Function
If , which pair of values for are correct?
First, set the quadratic function equal to :
Then, reduce the function to its two factors:
Since one of the factors on the left hand side of the equation must equal in order for the above equation to be true,
or
Solving for both, we get .