Flag 11 grade maths others> How do you find the terminal point on the...
question mark

How do you find the terminal point on the unit circle determined by t = 5π/12?

Aniket Singh , 1 Year ago
Grade
anser 1 Answers
Askiitians Tutor Team

To find the terminal point on the unit circle determined by \( t = \frac{5\pi}{12} \), follow these steps:

1. **Understand the unit circle and the parameter \( t \):**
- The unit circle is a circle of radius 1 centered at the origin \((0, 0)\) in the coordinate plane.
- The parameter \( t \) represents the radian measure of the angle swept counterclockwise from the positive x-axis.

2. **Express the angle \( t \) in terms of sine and cosine:**
- On the unit circle, the terminal point corresponding to an angle \( t \) is given by:
\[
(\cos t, \sin t)
\]
- This means we need to calculate \( \cos\left(\frac{5\pi}{12}\right) \) and \( \sin\left(\frac{5\pi}{12}\right) \).

3. **Simplify the angle \( t = \frac{5\pi}{12} \):**
- Break \( \frac{5\pi}{12} \) into known reference angles. Rewrite it as:
\[
\frac{5\pi}{12} = \frac{\pi}{4} + \frac{\pi}{6}
\]
- This allows us to use the angle sum identities for sine and cosine:
\[
\cos(a + b) = \cos a \cos b - \sin a \sin b
\]
\[
\sin(a + b) = \sin a \cos b + \cos a \sin b
\]
- Here, \( a = \frac{\pi}{4} \) and \( b = \frac{\pi}{6} \).

4. **Compute \( \cos\left(\frac{5\pi}{12}\right) \):**
- Using \( \cos(a + b) \):
\[
\cos\left(\frac{5\pi}{12}\right) = \cos\left(\frac{\pi}{4}\right)\cos\left(\frac{\pi}{6}\right) - \sin\left(\frac{\pi}{4}\right)\sin\left(\frac{\pi}{6}\right)
\]
- Substituting known values:
\[
\cos\left(\frac{\pi}{4}\right) = \frac{\sqrt{2}}{2}, \, \cos\left(\frac{\pi}{6}\right) = \frac{\sqrt{3}}{2}, \, \sin\left(\frac{\pi}{4}\right) = \frac{\sqrt{2}}{2}, \, \sin\left(\frac{\pi}{6}\right) = \frac{1}{2}
\]
- Perform the calculation:
\[
\cos\left(\frac{5\pi}{12}\right) = \frac{\sqrt{2}}{2} \cdot \frac{\sqrt{3}}{2} - \frac{\sqrt{2}}{2} \cdot \frac{1}{2}
\]
\[
\cos\left(\frac{5\pi}{12}\right) = \frac{\sqrt{6}}{4} - \frac{\sqrt{2}}{4}
\]
\[
\cos\left(\frac{5\pi}{12}\right) = \frac{\sqrt{6} - \sqrt{2}}{4}
\]

5. **Compute \( \sin\left(\frac{5\pi}{12}\right) \):**
- Using \( \sin(a + b) \):
\[
\sin\left(\frac{5\pi}{12}\right) = \sin\left(\frac{\pi}{4}\right)\cos\left(\frac{\pi}{6}\right) + \cos\left(\frac{\pi}{4}\right)\sin\left(\frac{\pi}{6}\right)
\]
- Substituting known values:
\[
\sin\left(\frac{5\pi}{12}\right) = \frac{\sqrt{2}}{2} \cdot \frac{\sqrt{3}}{2} + \frac{\sqrt{2}}{2} \cdot \frac{1}{2}
\]
- Perform the calculation:
\[
\sin\left(\frac{5\pi}{12}\right) = \frac{\sqrt{6}}{4} + \frac{\sqrt{2}}{4}
\]
\[
\sin\left(\frac{5\pi}{12}\right) = \frac{\sqrt{6} + \sqrt{2}}{4}
\]

6. **Write the terminal point:**
- The terminal point on the unit circle is:
\[
\left(\cos\left(\frac{5\pi}{12}\right), \sin\left(\frac{5\pi}{12}\right)\right)
\]
- Substituting the results:
\[
\left(\frac{\sqrt{6} - \sqrt{2}}{4}, \frac{\sqrt{6} + \sqrt{2}}{4}\right)
\]

Final answer:
The terminal point on the unit circle for \( t = \frac{5\pi}{12} \) is \( \left(\frac{\sqrt{6} - \sqrt{2}}{4}, \frac{\sqrt{6} + \sqrt{2}}{4}\right) \).

Last Activity: 1 Year ago
star
LIVE ONLINE CLASSES

Prepraring for the competition made easy just by live online class.

tv

Full Live Access

material

Study Material

removal

Live Doubts Solving

assignment

Daily Class Assignments