Chapter 7 - Pearson

Section 7.4 Vectors, Operations, and the Dot Product 10776. Using the law of cosines, we have2 2 2a + c -bcos B = 2ac2 2 26 + 5 - 4 36+ 25-16 3cos B = = =26 ( )( 5)60 42 2 2b + c -acos A = 2bc2 2 24 + 5 - 6 16+ 25-36 1cos A = = =24 ( )( 5)40 8Since2 æ3ö æ 9 ö 162cos B - 1= 2 - 1= 2-çè4÷ ø èç16ø÷162 1= = = cos A,A is twice the size of16 8B.77.210. 3921 mSection 7.4 Vectors, Operations, and theDot Product1. m and p; n and r.2. m and q, p and q, n and s, r and s.3. m= 1; p m= 2; t n= 1; r p=2t or1 1p= 1 m; t= m; r= 1 n;t=p2 24. m = –1q; p = –1q; r = –1s; q = –2t; n = –1s5.6.7.8.9.a = 34; b = 29; c = 1378. = 9.5 sq units79. A = 9.5 sq units (found using a calculator)80. A = 9.5 sq unitsChapter 7 Quiz(Sections 7.1−7.3)1. A » 1312. a » 201 m3. C » 48.0 4. 15.75 sq units10.11.5.2 = 189 km6. A» 41.6 or A» 138.47. C = 28 ;a» 648; b»4568. 3.6 mi9. 25.24983 mi.Copyright © 2013 Pearson Education, Inc.