a -2,I0 - 5andjd x B) -8 what is the value ofa- b ?(a) 4(c) 8b) 6(d) 1

1.	a -2,I0 - 5andjd x B) -8 what is the value ofa- b ?(a) 4(c) 8b) 6(d) 10
Answer» axb =a.bsin∅ = 8 and \|a\| = 2 and \|b\| = 5.so, axb = 2.5.sin∅ = 8=> sin∅ = 8/10 = 4/5. so cos∅ is √5²-4²/5 = 3/5 now , a.b = \|a\|.\|b\|cos∅ = 2.5.3/5 = 6. axb=a.bsinø but we don't know the value of a.b so u cannot use a.b as 2.5=10

a -2,I0 - 5andjd x B) -8 what is the value ofa- b ?(a) 4(c) 8b) 6(d) 10

Answer»

axb =a.bsin∅ = 8 and |a| = 2 and |b| = 5.so, axb = 2.5.sin∅ = 8=> sin∅ = 8/10 = 4/5. so cos∅ is √5²-4²/5 = 3/5

now , a.b = |a|.|b|cos∅ = 2.5.3/5 = 6.

axb=a.bsinø but we don't know the value of a.b so u cannot use a.b as 2.5=10