1. Main Ideas of Hon PreCalc Ch. 5 Class 1
Six Trigonometric Functions
Odd and Even Functions
Pythagorean Identities
sin2ө + cos2ө = 1
tan2ө + 1 = sec2ө
cot2ө + 1 = csc2ө
Cofunctions of complementary angles
sin ( 𝜋 2 – ө) = cos(ө)
cos( 𝜋 2 – ө) = sin(ө)
tan( 𝜋 2 – ө) = cot(ө)
sec( 𝜋 2 – ө) = csc(ө)
csc( 𝜋 2 – ө) = sec(ө)
cot( 𝜋 2 – ө) = tan(ө)
Applying Trigonometric Identities

2. Main Ideas of Hon PreCalc Ch. 5 Class 2
Solving Equations
Factoring
Problems with Multiples of Angles:
sin2x = 1/2
Using Inverses

3. Main Ideas of Hon PreCalc Ch. 5 Class 3
Sum and Difference Formulas
sin(x + y) = sinx cosy + cosx sin y
cos(x + y) = cosx cosy – sinx siny
sin(x - y) = sinx cosy - cosx sin y
cos(x - y) = cosx cosy + sinx siny
tan(x+y) = 𝑡𝑎𝑛𝑥+𝑡𝑎𝑛𝑦 1 − 𝑡𝑎𝑛𝑥𝑡𝑎𝑛𝑦
tan(x-y) = 𝑡𝑎𝑛𝑥−𝑡𝑎𝑛𝑦 1+ 𝑡𝑎𝑛𝑥𝑡𝑎𝑛𝑦