Transcript 5.4 Sum and Difference Formulas

5.4 Sum and Difference Formulas
In this section students will use sum and difference formulas to
evaluate trigonometric functions, verify identities, and solve
trigonometric equations.
Section 5.4, Sum and Difference
Formulas, pg. 368
Example 1
Find the exact value of cos75
Section 5.4, Sum and Difference
Formulas, pg. 368
Example 2
Find the exact value of sin

12
Section 5.4, Sum and Difference
Formulas, pg. 368
Example 3
Find the exact value of sin(u+v) given
12
 and
4 , where
cosv  
0u
sin u 
2
5
where

2
v 
13
Section 5.4, Sum and Difference
Formulas, pg. 368
Example 5
Prove the cofunction identity cos(

2
 x )  sin x
Section 5.4, Sum and Difference
Formulas, pg. 368
Example 6
Simplify the expression.
a. cos(  3 )
2
b.
tan(  3 )
Section 5.4, Sum and Difference
Formulas, pg. 368
Example 7


Find all solutions of sin( x  )  sin( x  )  1
4
4
in the interval [0,2 )