Fancy Trig Equations

To solve for an unknown angle we will use all sorts of clever tricks, employing the trig formulas and identities in weird and wonderful ways!

Proof of the Trig Sum and Difference Formulas

Proof of the sum and difference formulas for sine, cosine and tangent

Trig Substitution & Identities

Using the trig identities for substituting a Pythagorean looking expression.

Arithmetic Sequences

An Arithmetic Sequence is a pattern where each element changes by adding a constant. Here are examples, as well as the proof the formula for a partial sum of an arithmetic sequence.

Trig with Vectors, Complex Numbers, apps (Precalc 6)

Using the law of sines and cosines, we explor vectors, complex numbers and applications (aka "Word problems").

Using Sum & Difference Formulas

Here we find the trig functions of other angles based on the sum and difference of two angles, the double or half angle. We will prove these formulas in a different video

Some more Trig Word Problems (4.8, 4.R)

Here we use the trigonometry from our first Trig Chapter (4 in our textbook) to review how sine, cosine and tangent are used to solve word problems