Thomas Calculus 13th [Solutions]

Section 12.4 The Cross Product 897
i j k
38. AB 7i 4j and AD 2i 5j AB AD 7 4 0 43k area AB AD 43
2 5 0
39. AB 3i 2j 4k and DC 3i 2j 4k AB is parallel to DC; BC 2 i j and AD 2i j BC is
i j k
parallel to AD. AB BC 3 2 4 4i 8j 7k area AB BC 129
2 1 0
40. AC i 4j and DB i 4j AC is parallel to DB; AD i 3j 3k and CB i 3j 3k AD is
i j k
parallel to CB. AC AD 1 4 0 12i 3j 7k area AC AD 202
1 3 3
i j k
41. AB 2i 3j and AC 3i j AB AC 2 3 0 11k area 1 AB AC 11
2 2
3 1 0
i j k
42. AB 4i 4j and AC 3i 2j AB AC 4 4 0 4k area 1
2
3 2 0
AB
AC
2
i j k
43. AB 6i 5j and AC 11i 5j AB AC 6 5 0 25k area 1 AB AC 25
2 2
11 5 0
i j k
44. AB 16i 5j and AC 4i 4j AB AC 16 5 0 84k area 1
2
4 4 0
AB
AC
42
i j k
45. AB i 2j and AC i k AB AC 1 2 0 2i j 2k area 1 AB AC 3
2 2
1 0 1
i j k
46. AB i j k and AC 3i 3k AB AC 1 1 1 3i 3k area
3 0 3
1
3 2
AB AC
2 2
i j k
47. AB i 2j and AC j 2k AB AC 1 2 0 4i 2j k area
0 1 2
1
21
AB AC
2 2
Copyright
2014 Pearson Education, Inc.