Precalculus

# Key Equations

PrecalculusKey Equations

### Key Equations

 Law of Sines $sinα a = sinβ b = sinγ c a sinα = b sinβ = c sinγ sinα a = sinβ b = sinγ c a sinα = b sinβ = c sinγ$ Area for oblique triangles $Area= 1 2 bcsinα = 1 2 acsinβ = 1 2 absinγ Area= 1 2 bcsinα = 1 2 acsinβ = 1 2 absinγ$
 Law of Cosines $a 2 = b 2 + c 2 −2bccosα b 2 = a 2 + c 2 −2accosβ c 2 = a 2 + b 2 −2abcosγ a 2 = b 2 + c 2 −2bccosα b 2 = a 2 + c 2 −2accosβ c 2 = a 2 + b 2 −2abcosγ$ Heron’s formula
 Conversion formulas $cosθ= x r →x=rcosθ sinθ= y r →y=rsinθ r 2 = x 2 + y 2 tanθ= y x cosθ= x r →x=rcosθ sinθ= y r →y=rsinθ r 2 = x 2 + y 2 tanθ= y x$