maths formulas (edexcel)

• area of a trapezium

  $\frac{a+b}{2}\cdot h$

  
• volume of prism

  area of cross section x length
• quadratic formula

  ( -b ±√(b² - 4ac))/( 2a )
• sine rule

  sinA/a = sinB/b = sinC/c
• sine area rule

  (1/2)ab sinC
• cosine rule

  to find side c:

  A) length of side c

  B) length of side a

  C) length of side b

  D) angle opposite c

  
• alternate segment theorem

  the angle that lies between a chord and a tangent is equal to the angle subtended by the same chord in an alternate segment

  
• angle at centre

  angle at centre is twice the angle at the circumfrence

  
• angles in the same segment theorem

  angles in the same segment are equal

  
• angles in a semicircle

  the angle in a semi circle is 90 degrees

  
• chord of a circle

  a line drawn from the center of the circle to the middle of the chord is perpendicular to the chord

  
• cyclic quadrilateral

  the opposite angles in a cyclic quadrilateral sum to 180 degrees

  
• tangent of a circle

  the angle between a tangent and the radius of a circle is 90 degrees

  
• tangent of a circle

  tangents which meet at the same point are equal in length

  
• volume of a sphere

  (4/3)π r^3
• volume of a square based pyramid

  (length x width x height)/3
• exact trig values

  A) 0

  B) 1/2

  C) √2/2

  D) √3/3

  E) 1

  F) 0

  G) 1/2

  H) √2/2

  I) √3/3

  J) 1

  K) 0

  L) 1/√3

  M) 1

  N) √3