Maths formulae

• Area of triangle: 1/2absinC
• cos²A + sin²A = 1
• sec²A = 1 + tan²A
• cosec²A = 1 + cot²A
• sin2A = 2sinAcosA
• cos2A = cos²A - sin²A
• tan2A = 2tanA /1 - tan²A
• arc length = rθ
• Area of sector = 1/2r²θ
• Volume of cylinder

  πr²h
• Surface area of cylinder

  2πrh + 2πr²
• Volume of sphere

  4/3πr³
• Surface area of sphere

  4πr²
• Newton-raphson formula:

  xn+1 = xn – f(xn) / f’(xn)
• Integral of sin2x:

  ∫ ½(1-cos(2x))
• Integral of cos2x:

  ∫ ½(1+cos(2x))
• Other double angle formula:

  cos2θ=2cos²θ−1
• Other double angle formula:

  cos2θ=1−2sin²θ
• Integral of tanx:

  sec²x
• Integral of lnx:

  1/x