ACT Math : ACT Math

Study concepts, example questions & explanations for ACT Math

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Example Questions

Example Question #2961 : Act Math

Simplify the following expression:

 

 

Possible Answers:

tanΘ

None of the answers are correct

cscΘ

sin2Θ

cos2Θ

Correct answer:

sin2Θ

Explanation:

Convert cotΘ and secΘ to sinΘ and cosΘ and simplify the resulting complex fraction.

cotΘ =    cosΘ             secΘ = 1

              sinΘ               cosΘ

Example Question #2962 : Act Math

What is the reference angle for ?

Possible Answers:

Correct answer:

Explanation:

The reference angle is between  and , starting on the positive -axis and rotating in a counter-clockwise manor.

To find the reference angle, we subtract  for each complete revolution until we get a positive number less than .

is equal to two complete revolutions, plus a  angle. Since is in Quadrant II, we subtract it from to get our reference angle:

Example Question #2963 : Act Math

Unit_circle

In the unit circle above, if , what are the coordinates of ?

Possible Answers:

Correct answer:

Explanation:

On the unit circle, (X,Y) = (cos Θ, sin Θ).

(cos Θ,sin Θ) = (cos 30º, sin 30º) = (√3 / 2 , 1 / 2)

Example Question #44 : Trigonometry

What is the reference angle for ?

Possible Answers:

Correct answer:

Explanation:

A reference angle is the smallest possible angle between a given angle measurement and the x-axis.

In this case, our angle  lies in Quadrant I, so the angle is its own reference angle.

Thus, the reference angle for  is .

Example Question #51 : Trigonometry

What is the reference angle for ?

Possible Answers:

Correct answer:

Explanation:

A reference angle is the smallest possible angle between a given angle measurement and the x-axis.

In this case, our angle  lies in Quadrant III, so the angle is found by the formula .

  

Thus, the reference angle for  is .

Example Question #52 : Trigonometry

What is the reference angle for ?

Possible Answers:

Correct answer:

Explanation:

A reference angle is the smallest possible angle between a given angle measurement and the x-axis.

In this case, our angle  lies in Quadrant II, so we can find our reference angle using the formula

.

  

Thus, the reference angle for  is .

Example Question #1 : Sine

What is the period of 2sin(4Θ)?

Possible Answers:

None of the answers are correct

Correct answer:

Explanation:

 The period of sinΘ is 2Π, so we set the new angle equal to the base period of 2Π and solve for Θ.

So 4Θ = 2Π and Θ = Π/2.

Example Question #1 : How To Find The Period Of The Sine

A function with period P will repeat on intervals of length P, and these intervals are referred to as periods.

 

Find the period of 

.

Possible Answers:

Correct answer:

Explanation:

For the function

the period is equal to

in this case

which reduces to .

Example Question #2964 : Act Math

A function with period P will repeat on intervals of length P, and these intervals are referred to as periods.

Find the period of the function

.

Possible Answers:

Correct answer:

Explanation:

For the function

the period is equal to

in this case

which reduces to .

Example Question #3 : How To Find The Period Of The Sine

What is the period of the function ?

Possible Answers:

Correct answer:

Explanation:

To find the period of Sine and Cosine functions you use the formula:
 where  comes from . Looking at our formula you see b is 4 so 

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