- #1
meson0731
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Homework Statement
Given vector a and b, let vector v = (|a|b + |b|a) / (|a| + |b|). Show that vector v bisects the angle created by vector b and a.
Homework Equations
cos(θ) = a dot b / (|a||b|)
The Attempt at a Solution
I used the dot product equation to find angle between a and v.
cosθ = (a dot v) / |a||v|
i substituted ((|a|b + |b|a) / (|a| + |b|)) for v.
cosθ = (a dot ((|a|b + |b|a) / (|a| + |b|)) / |a||v|
I distributed the (a dot ((|a|b + |b|a)
cosθ ( ((|a|b dot a) + (|b| |a|^2) ) / (|a| + |b|)) / (|a||b|)
I then tried to get the cosθ of b dot w to the same thing. I tried to get the two angles equal to each other. My idea is that if the angles formed by a and v and b and v are equal then v bisects the two angles.