Given two unit vectors a and b | Mathematics | Page 1

broken nebula Mar 25, 2025, 3:50 PM

#

We know that vector 5a-3b is perpendicular to vector 2a+b find the angle between
a and b.

minor oracleBOT Mar 25, 2025, 3:50 PM

#

signal flame Mar 25, 2025, 3:51 PM

#

did u write that correctly?

broken nebula Mar 25, 2025, 3:58 PM

#

Why?

#

Honestly I might not have. i had this on a test

#

Should I just do (5a-3b)(2a+b)
10a^2 - ab -3b^2 and that =0

#

And a^2 ans b ^2 are 1

#

?

narrow citrus Mar 25, 2025, 4:04 PM

#

yep

#

so what do you get

broken nebula Mar 25, 2025, 4:04 PM

#

And that cant be 7 right

#

Because imma have to take the cosine

#

Damn

narrow citrus Mar 25, 2025, 4:05 PM

#

wait, hold up let me think this through

broken nebula Mar 25, 2025, 4:08 PM

#

a•b = cos(x)11 since both are unit vectors
So I just use a calculator to get cos^-1 of whatever is on the right

#

I think I got it now

#

I jist dont rember it correctly because I dont think its gonna be 7 cuz there would be no solutions

narrow citrus Mar 25, 2025, 4:09 PM

#

that's not right, it can't be 7

#Given two unit vectors a and b