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garri49 [273]
3 years ago
13

IfA = i +3j -2K and B=4i-2j+4kFind (2A+B).(A-2B)​

Mathematics
1 answer:
Marizza181 [45]3 years ago
8 0

GIVEN :

a = 1/√10 ( 3i + k) and

b = 1/7 ( 2i + 3j - 6k)

TO FIND :

( 2a- b) . [ ( a x b ) x ( a + 2b)]

SOLUTION :

◆Going with the equation given,

( 2a - b) . [ ( a x b ) x ( a + 2b)]

= (2a - b) [( a×b×a) + 2(a×b)×b]

◆BAC - CAB RULE,

A×B×C = B( A.B ) - C(A.B )

= (2a- b ) [ (b (a.a ) - a (a.b ) + 2b ( a.b) -2b (a.b]

Solving further

= (2a - b )(b - 2a)

= -4a.a -b.b

=-5.

Answer:

( 2 - b) . [ ( a x b ) x ( a + 2b)] = -5

Hoped I helped

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Help me for 20 points.
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In a geometric sequence, the ratio between consecutive terms is...
Leokris [45]
<h3>Answer: The same or equal</h3>

========================================================

Explanation:

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lina2011 [118]
1) 180 - 74 = 106
2) 135 
3) 140
4) 65
5) 107

hope they help
if u need work and explanations... then tell me .. i will show thereafter
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