Some Important Formulas

1. Binomial theorem

8. .

20.     or
        or
    

36. If is the angle between two lines whose slopes are and , then

37. Two lines whose slopes are and are parallel if and are perpendicular if .

38. Transforming from polar coordinates to rectangular coordinates

39. The area of a triangle with length sides , , and is where is half the perimeter or .

40. Volume of a sphere of radius :

41. Surface area of a sphere of radius :

42. Volume of a rectangular pyramid

    

43. Volume of a frustum of pyramid of height and of base areas and :

    

44. Volume of a cone of radius and height

45. Lateral area of a cone of radius and height : . This can also be written as , where is its slant height.