All ACT Math Resources
Example Questions
Example Question #192 : Coordinate Plane
Electrical power can be generated by wind, and the magnitude of power will depend on the wind speed. A wind speed of (in
) will generate a power of
. What is the minimum wind speed needed in order to power a device that requires
?
The simplest way to solve this problem is to plug all of the answer choices into the provided equation, and see which one results in a power of
.
Alternatively, one could set up the equation,
and factor, use the quadratic equation, or graph this on a calculator to find the root.
If we were to factor we would look for factors of c that when added together give us the value in b when we are in the form,
.
In our case . So we need factors of
that when added together give us
.
Thus the following factoring would solve this problem.
Then set each binomial equal to zero and solve for v.
Since we can't have a negative power our answer is .
Example Question #193 : Coordinate Plane
Compared to the graph , the graph
has been shifted:
units to the left.
units to the right.
units up.
units down.
units down.
units to the left.
The inside the argument has the effect of shifting the graph
units to the left. This can be easily seen by graphing both the original and modified functions on a graphing calculator.
Example Question #831 : Act Math
The graph of passes through
in the standard
coordinate plane. What is the value of
?
To answer this question, we need to correctly identify where to plug in our given values and solve for .
Points on a graph are written in coordinate pairs. These pairs show the value first and the
value second. So, for this data:
means that
is the
value and
is the
value.
We must now plug in our and
values into the original equation and solve. Therefore:
We can now begin to solve for by adding up the right side and dividing the entire equation by
.
Therefore, the value of is
.
Example Question #1 : How To Graph Complex Numbers
Point A represents a complex number. Its position is given by which of the following expressions?
Complex numbers can be represented on the coordinate plane by mapping the real part to the x-axis and the imaginary part to the y-axis. For example, the expression can be represented graphically by the point
.
Here, we are given the graph and asked to write the corresponding expression.
not only correctly identifies the x-coordinate with the real part and the y-coordinate with the imaginary part of the complex number, it also includes the necessary
.
correctly identifies the x-coordinate with the real part and the y-coordinate with the imaginary part of the complex number, but fails to include the necessary
.
misidentifies the y-coordinate with the real part and the x-coordinate with the imaginary part of the complex number.
misidentifies the y-coordinate with the real part and the x-coordinate with the imaginary part of the complex number. It also fails to include the necessary
.
Example Question #1 : How To Graph Complex Numbers
Which of the following graphs represents the expression ?
Complex numbers cannot be represented on a coordinate plane.
Complex numbers can be represented on the coordinate plane by mapping the real part to the x-axis and the imaginary part to the y-axis. For example, the expression can be represented graphically by the point
.
Here, we are given the complex number and asked to graph it. We will represent the real part,
, on the x-axis, and the imaginary part,
, on the y-axis. Note that the coefficient of
is
; this is what we will graph on the y-axis. The correct coordinates are
.
Example Question #11 : Graphing
The point is on the graph of
. What is the value of
?
Because points on a graph are written in the form of , and the point given was
, this means that
and
.
In order to solve for , these values for
and
must be plugged into the given equation. This gives us the following:
We then solve the equation by finding the value of the right side, then dividing the entire equation by 5, as follows:
Therefore, the value of is
.
Example Question #1 : How To Graph A Function
The Y axis is a _______________ of the function Y = 1/X
Asymptote
Vertical slope
Equation
Zero solution
Asymptote
A line is an asymptote in a graph if the graph of the function nears the line as X or Y gets larger in absolute value.
Example Question #1 : How To Graph A Function
Which of the given functions is depicted below?
The graph has x-intercepts at x = 0 and x = 8. This indicates that 0 and 8 are roots of the function.
The function must take the form y = x(x - 8) in order for these roots to be true.
The parabola opens downward, indicating a negative leading coefficient. Expand the equation to get our answer.
y = -x(x - 8)
y = -x2 + 8x
y = 8x - x2
Therefore, the answer must be y = 8x - x2
Example Question #3 : How To Graph A Function
What is the domain of the following function:
x ≠ –1
x = all real numbers
x ≠ 5
x ≠ 2
x ≠ –2 and x ≠ –3
x ≠ –2 and x ≠ –3
The denominator cannot be zero, otherwise the function is indefinite. Therefore x cannot be –2 or –3.
Example Question #262 : Coordinate Geometry
The figure above shows the graph of y = f(x). Which of the following is the graph of y = |f(x)|?
One of the properties of taking an absolute value of a function is that the values are all made positive. The values themselves do not change; only their signs do. In this graph, none of the y-values are negative, so none of them would change. Thus the two graphs should be identical.
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