1. Bearing
2. Phytagoras Theorem
3. Trigonometric Ratio
4. Angle of elevation and depression
5. Sine and cosine value
6. Sine and Cosine Rule
7. Area of triangle
8. Angle between Line and Plane
1. Sketching and Using graph of Trigonometric Function
Graphs of Sine, Cosine and Tangent
Here are some nice graphs to look at ...
Plot of Sine
The Sine Function has this beautiful up-down curve (which repeats every 2Ï€ radians, or 360°).
It starts at 0, heads up to 1 by Ï€/2 radians (90°) and then heads down to -1.
Plot of Cosine
Cosine is just like Sine, but it starts at 1 and heads down until Ï€ radians (180°) and then heads up again.
Plot of Sine and Cosine
In fact Sine and Cosine are like good friends: they follow each other, exactly "Ï€/2" radians, or 90°, apart.
Plot of the Tangent Function
The Tangent function has a completely different shape ... it goes between negative and positive Infinity, crossing through 0 (every Ï€ radians, or 180°), as shown on this plot.
At Ï€/2 radians, or 90° (and -Ï€/2, 3Ï€/2, etc) the function is officially undefined, because it could be positive Infinity or negative Infinity.