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The angle between vecA = hati + hatj and...

The angle between `vecA = hati + hatj and vecB = hati - hatj` is

A

`45^(@)`

B

`90^(@)`

C

`-45^(@)`

D

`180^(@)`

Text Solution

Verified by Experts

The correct Answer is:
B
(b ) Given ,`A=hati +hatj`
and `B=hati-hatj`
We know that
A.B=|A||b|cos theta `
implies (hati+hatj).(hati-hatj)=(sqrt(1+1))(sqrt(1+1)) costheta`
where `theta` is the angle between A and B
`implies cos theta=(1-0+0-1)/(sqrt(2)sqrt(2))=(0)/(2)=0`
`implies theta90^(@)`
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