11.8 Unit Circle
Term 3
Radian measure · Full unit circle · Arc length, sector and segment area · Special triangles, exact values · Negative-angle, complementary-angle and Pythagorean identities · sin/cos/tan equations
Learning Objectives
PrintRadian Measure and the Unit Circle (Extended)
- 1. Convert between degrees and radians; understand radian measure as arc length on the unit circle.
- 2. Use the full unit circle to define $\sin\theta$, $\cos\theta$ and $\tan\theta$ for any angle.
- 3. Use special triangles to find exact trigonometric values at multiples of $\frac{\pi}{6}$, $\frac{\pi}{4}$, $\frac{\pi}{3}$.
- 4. Apply negative-angle and complementary-angle identities.
- 5. Apply the Pythagorean identity $\sin^2\theta + \cos^2\theta = 1$ and $\tan\theta = \dfrac{\sin\theta}{\cos\theta}$.
- 6. Solve trigonometric equations of the form $\sin x = k$, $\cos x = k$, $\tan x = k$ in radians.
- 7. Calculate arc length, sector area and segment area in radians.
- 8. Calculate arc length, sector area and segment area in degrees.
Review Pack
Open review hub
Fluency Pack A — 40 questions
Fluency Pack B — 40 questions
Problem-solving — 12 unfamiliar tasks
Worked solutions (Pack A + B + problems)