Brainlag PlusExact values of sin, cos and tan of 0°, 30°, 45°, 60° and 90° from two special triangles, then Pythagoras and trigonometry in cuboids and pyramids (Higher).
Two triangles give every value
Cut a square with sides 1 along its diagonal: the hypotenuse is √2 and both angles are 45°.
Cut an equilateral triangle with sides 2 in half: the sides are 1, √3 and 2, with angles 30° and 60°.
| 0° | 30° | 45° | 60° | 90° | |
|---|---|---|---|---|---|
| sin | 0 | 1/2 | √2/2 | √3/2 | 1 |
| cos | 1 | √3/2 | √2/2 | 1/2 | 0 |
| tan | 0 | √3/3 | 1 | √3 | no value |
√2/2 is the same as 1/√2, and √3/3 is the same as 1/√3. All tiers need this table.
The rest of this lesson and its 7 practice questions are in Plus.
Screen 1 of 3, free to read.
- 7 exam-style questions, marked as you go, each with a worked solution
- The Unit Circle beside every question
- Anything you get wrong is saved to your flashcards