AP Pre Cal formulas

Pythagorean identity (cos and sin)

cos²+sin²=1

Pythagorean identity (tan and sec)

1+tan²=sec²

Pythagorean identity (cot and csc)

cot²+1=csc²

Double angle- Sin

sin(2θ) = 2sin(θ)cos(θ)

Double angle-Cos

cos(2θ) = 2cos²(θ) - 1

sin(a+b)

sin(a)cos(b) + cos(a)sin(b)

cos(a+b)

cos(a)cos(b) - sin(a)sin(b)

Polar coords

r,θ

Radius from rectangular coordinates

(x² + y²) =r²

Theta from rectangular coordinates

θ = tan⁻¹(y/x)

Polar to rectangular

x=rcos(θ) and y=rsin(θ)