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Magnitude of vector question

I have a vector question that I have no clue how to solve. Any help you guys could give would be amazing!

Given that a.b = 5 and a.(a+b) = 54, find the magnitude of |a|
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Avatar for Zacken
Zacken
22
Original post by LewisG_
I have a vector question that I have no clue how to solve. Any help you guys could give would be amazing!

Given that a.b = 5 and a.(a+b) = 54, find the magnitude of |a|


a⋅(a+b)=a⋅a+a⋅b=∣a∣+a⋅b=54a \cdot (a+b) = a\cdot a + a\cdot b = |a| + a\cdot b = 54
Original post by LewisG_
I have a vector question that I have no clue how to solve. Any help you guys could give would be amazing!

Given that a.b = 5 and a.(a+b) = 54, find the magnitude of |a|


since the scalar product is distributive...

a.(a+b) can be written as

a.a + a.b

that should help...
Reply 3
Avatar for LewisG_
LewisG_
OP
Original post by Zacken
a⋅(a+b)=a⋅a+a⋅b=∣a∣+a⋅b=54a \cdot (a+b) = a\cdot a + a\cdot b = |a| + a\cdot b = 54


Thanks, I got it

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