ACT · Trigonometry · Graphs of sine and cosine
Question act-q-00556
Medium Multiple choice No calculator
The question
What is the value of sin(60°)?
- ½
- 1
- 0
- √3/2
Show answer & worked solution
Answer: √3/2
Worked solution. Recall the unit circle: sin(60°) = √3/2.
Why each wrong choice is wrong. The classic distractor swaps sine and cosine values for the same angle. Drilling the unit circle eliminates this entirely.
Test-day tactic. Memorize sine and cosine at 0°, 30°, 45°, 60°, and 90°. The values are short and they appear constantly.
About this question type
Items test the basic shape of sine and cosine graphs and the effect of changing amplitude, period, and phase shift.
You will see a question shaped like this one on roughly every other official ACT form, typically at a moderate position in the section — solidly within the range that separates a 600-band student from a 700-band student. Treat any miss in this subtopic as a signal to drill the subtopic page before you do another full practice test.