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Playlist ACT® Trigonometry 25 videos
ACT Math Trigonometry Drill 1, Problem 2. Can you find the tangent?
ACT Math: Trigonometry Drill 1, Problem 3. Can you find the cosine?
ACT Math: Trigonometry Drill 1, Problem 4. Can you find the sine?
ACT Math 5.2 Trigonometry 228 Views
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Description:
ACT Math: Trigonometry Drill 5, Problem 2. What is the measure of Angle x?
- Trigonometry / SOHCAHTOA (values and properties of trig functions)
- Trigonometry / Solving right triangles
- Product Type / ACT Math
- Foreign Language / Arabic Subtitled
- Foreign Language / Korean Subtitled
- Foreign Language / Chinese Subtitled
- Foreign Language / Spanish Subtitled
- Trigonometry / Trigonometric relations in right triangles
Transcript
- 00:03
Here's your shmoop du jour.
- 00:05
If sin(x) = 1/2, what is the measure of Angle x?
- 00:07
And here are the options:
- 00:11
Ok, so this question wants to know the measure
- 00:13
of angle X.
Full Transcript
- 00:15
According to SOHCAHTOA,
- 00:16
the sine is opposite over hypotenuse.
- 00:20
So if sin(x) equals one over two, one is the length of the side opposite angle x and two
- 00:27
is the adjacent side, or the hypotenuse. Using the Pythagorean theorem, we can solve
- 00:32
for the length of the missing leg.
- 00:37
1 squared plus the leg squared equals 2 squared. This simplifies to 1 plus the leg squared
- 00:44
equals 4.
- 00:45
Subtract 1 from both sides, and we get that the leg squared equals 3. Take the square
- 00:51
root of both sides, and the leg equals square root of 3.
- 00:54
This makes the ratio of the sides, 1 to the square root of 3 to 2, making this a special 30-60-90 triangle.
- 01:02
x, the angle opposite the smallest side length, is the smallest angle, or 30 degrees.
- 01:08
So it's A.
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