Disclaimer: The material in the videos below comes mainly from outside City Tech. The presentation in these videos may differ from the one given in your class. Please consult with your instructor to confirm whether a particular approach is acceptable in your class.
Trigonometric function values
- $\rhd$ Trig values of special angles (7:53) Sal finds the trig values of $\frac{\pi}{4}$ on the unit circle using triangles.
- $\rhd$ How To Find The Exact Values of Trig Functions (12:38) Computes, for example, $\cos(240^\circ)$ (at 6:20), $\tan(-45^\circ)$ (at 7:40), $\sin(\frac{10\pi}{3})$ (at 9:00)
- * Trig values of special angles Students are asked to find the trig values of angles such as $-\frac{2\pi}{3} $without using a calculator.
- $\rhd$ Unit circle definition of trig functions (9:03) How to extend SOH-CAH-TOA to define trigonometric functions (sine, cosine, and tangent) for all real numbers.
Angle Measure: Introduction to Radians
- $\rhd$ Introduction to radians (10:51) This video explains the definition and motivation for radians and the relationship between radians and degrees, including the identities by which we can convert between radians and degrees.
- $\rhd$ Radians and degrees (7:12) Sal discusses the general approach to converting between radians and degrees and vice versa. Describes identities, then converts
degrees to radians — including nice explanation of unit conversion. Also converts
degrees to radians and $-\frac \pi 2$ radians to degrees.
- $\rhd$ Converting degrees to radians (7:01) This video shows how to convert the degree measures $150^\circ$ and $-45^\circ$ to radians.
- $\rhd$Converting radians to degrees (3:19) Converts $\pi$ and $-\frac \pi 3$ radians to degrees.
- * Converting from radians to degrees and visa versa Assorted example problems.
- $\rhd$ Radians and Quadrants (3:51) This video show how to find the quadrant in which a ray formed by rotation of $\theta$ radians lies. Examples: $\frac{3\pi}5$, $\frac{2\pi}7$.
