# Trigonometry - Most important formulas

1. $sin^2\alpha+cos^2\alpha=1$

2. $sec^2\alpha - tan^2 \alpha=1$

3. $sce^2\alpha-cot^2\alpha=1$

4. $tan\alpha={sin\alpha \over cos \alpha}$

5. $cot\alpha={cos\alpha \over sin \alpha}$

6. $tan\alpha .cot\alpha=1$

7. $sce\alpha={1 \over cos\alpha}$

8. $cosec\alpha={1 \over sin\alpha}$