Module 5: Lesson 4

 

Self-Check 3

2. Questions 7, 8.b., 8.c., 10, 20.b., and 20.c. on pages 306 and 307 of the textbook
   7. 
   8.  
      2. 
         
      3. 
   10.  
   20.  
       2. can be thought of as a triangle with a hypotenuse of 5 and a side of 4. The Pythagorean theorem can be used to determine the third side.
          
          
           
          
          
          Both angles are in quadrant 1, so the positive 3 is the third side of the triangle. So  sin B can be calculated in a similar fashion.
          
          
           
          
          
          Again, the positive value is used and so
          
          Substituting these into the sum identity gives
          
          
           
          
       3. 

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