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Question : 73 of 120
Marks:
+1,
-0
Solution:
We are given that "sum of two vectors
and
is a vector
".
⇒+= Taking dot product of both sides with themselves, the magnitudes will still be equal:
⇒(+).(+)=().() ⇒||2+||2+2.=||2 Since
||=||=||=2, we get:
⇒22+22+2.=22 ⇒4+4+2.=4 ⇒2.=−4 Now,
|−|2=(−).(−) =||2+||2−2. =4+4−(−4) =12 ⇒|−|=√12=2√3
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