This site is under construction.Features and pricing shown here are still being built and may change.
← Trigonometry
Semester 2

Analytic Trig, Applications, Polar and Vectors

You prove and use the trig identities, solve trig equations, apply trig to real triangles with the laws of sines and cosines, and finish with polar coordinates, complex numbers and vectors.

Class 1

Trigonometric identities

The equations that are always true, and why they help.

Class 2

Sum and difference formulas

The angle-adding formulas, and what they unlock.

Class 3

Double-angle and half-angle formulas

Formulas for twice an angle and half an angle.

Class 4

Product-to-sum and sum-to-product formulas

Turning products of trig functions into sums, and back.

Class 5

Trigonometric equations

Finding the angles that make a trig equation true.

Class 6

Right triangle applications

Solving real problems with a right triangle.

Class 7

The law of sines

Solving triangles that are not right-angled.

Class 8

The law of cosines and area

The other law for hard triangles, and finding area.

Class 9

Polar coordinates

Locating a point by angle and distance.

Class 10

Polar equations and graphs

The pretty curves polar equations draw.

Class 11

Complex numbers in polar form

Writing and powering complex numbers with trig.

Class 12

Vectors and the dot product

Quantities with size and direction, and how to combine them.