[tex]\vec{a}\cdot\vec{b}[/tex] gives .
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Hey,
I am working through work on the dot product and came across this question:
Let a be a unit vector and let |b| = 4. Let the angle between these two vectors be 30 degrees. Calculate (2a - b) DOT (5a + 3b).
*Don't know how to make the arrow above the letters, pretend it is above all a's and b's. Also, the DOT is how I am going to say dot product like the formula for the dot product of two vectors with an angle theta between them is: u DOT v = |u| |v| cos(theta).
I am unsure of how to proceed with this question. I am assuming that I put this through the DOT formula. But am unsure of how to set this up.
Help?
Let a be a unit vector and let |b| = 4. Let the angle between these two vectors be 30 degrees. Calculate (2a - b) DOT (5a + 3b).
If a is a unit vector, let it equal {1,0,0}
then by taking the sin and cos of 30, we know that b would be
but since |b|=4, b is really equal to
now that you know a and b, you should be able to do those dot products pretty easily.