ACT Math : Algebra

Study concepts, example questions & explanations for ACT Math

varsity tutors app store varsity tutors android store varsity tutors ibooks store

Example Questions

Example Question #74 : Graphing

Give the horizontal asymptote of the graph of the function 

Possible Answers:

The graph has no horizontal asymptote.

Correct answer:

Explanation:

We can rewrite this as follows:

This is a translation of the graph of , which has  as its horizontal asymptote, to the right two units and down three units. Because of the latter translation, the horizontal asymptote is .

Example Question #1 : How To Graph An Exponential Function

If the functions 

were graphed on the same coordinate axes, what would be the -coordinate of their point of intersection?

Round to the nearest tenth, if applicable.

Possible Answers:

The graphs of  and  would not intersect.

Correct answer:

Explanation:

We can rewrite the statements using  for both  and  as follows:

To solve this, we can multiply the first equation by , then add:

      

            

Example Question #2 : How To Graph An Exponential Function

If the functions 

were graphed on the same coordinate axes, what would be the -coordinate of their point of intersection?

Round to the nearest tenth, if applicable.

Possible Answers:

The graphs of  and  would not intersect.

Correct answer:

Explanation:

We can rewrite the statements using  for both  and  as follows:

To solve this, we can set the expressions equal, as follows:

Example Question #451 : Advanced Geometry

If this is a sine graph, what is the phase displacement?Screen_shot_2013-07-16_at_10.04.45_am

Possible Answers:

0

π

2π

4π

(1/2)π

Correct answer:

0

Explanation:

The phase displacement is the shift from the center of the graph. Since this is a sine graph and the sin(0) = 0, this is in phase.

Example Question #1 : How To Find Transformation For An Analytic Geometry Equation

If this is a cosine graph, what is the phase displacement?Screen_shot_2013-07-16_at_10.04.45_am

Possible Answers:

2π

(1/2)π

π

0

4π

Correct answer:

π

Explanation:

The phase displacement is the shift of the graph. Since cos(0) = 1, the phase shift is π because the graph is at its high point then.

Example Question #1 : Transformation

A regular pentagon is graphed in the standard (x,y) coordinate plane. Which of the following are the coordinates for the vertex P?

Screen_shot_2013-06-03_at_1.02.45_pm

Possible Answers:

Correct answer:

Explanation:

Regular pentagons have lines of symmetry through each vertex and the center of the opposite side, meaning the y-axis forms a line of symmetry in this instance. Therefore, point P is negative b units in the x-direction, and c units in the y-direction. It is a reflection of point (b,c) across the y-axis.

Example Question #1 : Transformation

If g(x) is a transformation of f(x) that moves the graph of f(x) four units up and three units left, what is g(x) in relation to f(x)?

Possible Answers:

Correct answer:

Explanation:

To solve this question, you must have an understanding of standard transformations. To move a function along the x-axis in the positive direction, you must subtract the value from the operative x-value. For example, to move a function, f(x), five units to the left would be f(x+5).

To shift a function along the y-axis in the positive direction, you must add the value to the overall function. For example, to move a function, f(x), three units up would be f(x)+3.

The question asks us to move the function, f(x), left three units and up four units. f(x+3) will move the function three units to the left and f(x)+4 will move it four units up.

Together, this gives our final answer of f(x+3)+4.

Example Question #2 : Transformation

What is the period of the function?

Screen_shot_2013-07-16_at_10.04.45_am

Possible Answers:

4π

2π

1

π

3π

Correct answer:

4π

Explanation:

The period is the time it takes for the graph to complete one cycle.

In this particular case we have a sine curve that starts at 0 and completes one cycle when it reaches .

Therefore, the period is 

Example Question #1 : Linear / Rational / Variable Equations

n/17 = 54/9

What is the value of n?

Possible Answers:

None of the above.

85

93.5

54

102

Correct answer:

102

Explanation:

Cross multiply: 9n = 54 * 17 → n = (54 * 17)/9 = 102.

This also can be solved by reducing the right hand side of the equation, so n/17 = 6. 

Example Question #1 : Linear / Rational / Variable Equations

If 12x + 3 = 2(5x + 5) + 1, what is the value of x?

Possible Answers:

6

5

7

4

3

Correct answer:

4

Explanation:

Starting with 12x + 3 = 2(5x + 5) + 1, we start by solving the parenthesis, giving us 12x + 3 = 10x + 11. We then subtract 10x from the right side and subtract three from the left, giving us 2x = 8; divide by 2 → x = 4.

Learning Tools by Varsity Tutors