0I always see student's are using table to find the value of a trigonometric ratio.
I have a better way:
For a right angle triangle ABC, where angle B is 90 degree. We know:
| SinC = AB/AC | CosecC = AC/AB |
| CosC = BC/AC | SecC = AC/BC |
| TanC = AB/BC | CotC = BC/AB |
Remember:
| For C = 0 degree: | AB = 0, BC = 1, AC = 1 |
| For C = 30 degree | AB = 1, BC =√3, AC2 |
| For C = 45 degree | AB = 1, BC = 1, AC = √2 |
| For C = 60 degree | AB = √3, BC = 1, AC = 2 |
| For C = 90 Degree | AB = 1, BC = 0, AC = 1 |
Draw the figures with above condition and find the all trigonometric ratios.
You can see that there are 5 different angle but growing 3 triangle is enough. Because triangle of 60 degree can be made by rotating the triangle of 30 degree. Similarly we can get triangle of 90 degree from triangle of 0 degree.
Now draw all the figures and try to find the trigonometric ratio. If you set all the figures in your mind it will too easy to find the value of all trigonometric ratio.
It seems to be very hard but it's so easy to use and must save time.
