1.7 precalc

Limaçon type (a + b cosθ or sinθ):

  • a/b < 1 → inner loop

  • a/b = 1 → cardioid

  • 1 < a/b < 2 → dimple

  • a/b ≥ 2 → convex

Rose curves (a cos nθ or sin nθ):

  • n odd → n petals

  • n even → 2n petals

Circles:

  • r = constant → center at pole

  • r = a cosθ → x-axis, r = a sinθ → y-axis

Lemniscate:

  • r² = a² cos 2θ or sin 2θ → figure 8

Line:

  • r=n/sin0

  • r=n/cos0

θ = π/2

  • (-r,-θ)

Polar Axis

  • (r,-θ)

Pole

  • (-r,θ)

Polar Form of Complex Number

Polar Form of a Complex Number

  • z=r(cosθ+isinθ)

  • r=∣z∣= sqrt(a²+b²)