Lesson 39- Solving Trig Functions

Equations    vs.      Identites

Equations:  There are 3 different methods to solve an equation
Method One- Solve algerbracially (Draw SPA)
Method Two-  Solve by graphing (use calc.)
put the left side of the eq'n in y1 and the right side of the eq'n in y2
to find what x equals use 2nd trace (=calc) intersection
           example:  eq'n  Sin(x) = 0.35
                                   y1= Sin(x)    y2= 0.35
Method Three- * most used and easiest*
1) Set = 0
2) put eq'n set to 0 into y1
to find what x equals use calc and zeros

Creating general soultions:
a genernal soultion is for stating the point easily when the graph repeats, just add the period and n
ex.
Sin(x) = 0.35     period= 2π
x= 0.36 + 2πn
n is an interger


* Note: for both graphing methods you must create a view screen (graph) and state the domain and range


Example:
3 + Sin2x = 1 - 5sin2x         collect like terms and set to 0!
6sin2x + 2 = 0
x= 1.74 + πn, 2.97 + πn    n is a interger