Precalculus

# Key Equations

PrecalculusKey Equations
 Law of Sines $sin α a = sin β b = sin γ c a sin α = b sin β = c sin γ sin α a = sin β b = sin γ c a sin α = b sin β = c sin γ$ Area for oblique triangles
 Law of Cosines $a 2 = b 2 + c 2 −2bccos α b 2 = a 2 + c 2 −2accos β c 2 = a 2 + b 2 −2abcos γ a 2 = b 2 + c 2 −2bccos α b 2 = a 2 + c 2 −2accos β c 2 = a 2 + b 2 −2abcos γ$ Heron’s formula
 Conversion formulas $cos θ= x r →x=rcos θ sin θ= y r →y=rsin θ r 2 = x 2 + y 2 tan θ= y x cos θ= x r →x=rcos θ sin θ= y r →y=rsin θ r 2 = x 2 + y 2 tan θ= y x$