# Trigonometry

• ### Formulas of Inverse Trigonometric Functions

1) 2) 3) 4) 5) 6) 7)

• ### Formulas of Trigonometric and Logarithmic Functions

1) 2) 3) 4) 5) 6) 7) 8)

• ### Change of Hyperbolic Functions

1) 2) 3) 4) 5) 6)

• ### Circles Connected with a Triangle

1) If denotes in-radius, then   2) Circum radius is given by   3) If denotes radii, then   4)   5) In an equilateral triangle

• ### Results and Formulas of Plane Triangles

Consider the triangle, having the angles and sides as shown in the figure.   1) Law of Sine is   2) Laws of Cosine are or   or   or 3) Laws of Tangent are   HALF ANGLE FORMULAS Consider that and are sides and angles of , as shown above, also if (i) (ii) […]

• ### Results of Trigonometric Ratios of Allied Angles

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. Period of and is, whereas period of and is . If is any integer, then 23. 24. 25. 26. 27. 28.

• ### Fundamental Trigonometric Ratios

1) 2)     3) 4) 5) 6) 7) Signs of trigonometric Ratios     I QUADRANT: , means all trigonometric ratios are positive.    II QUADRANT: , means and are positive all others are negative.   III QUADRANT: , means and are positive all others are negative.   IV QUADRANT: , means and are positive all others […]