Question

Help finding lwl screenshot is attached. @dan815

v*w=10?
lwl=?

Answer 1

@zepdrix

Answer 2

Sec, thinking.
I'm a little rusty with vectors >.<

Answer 3

No worries!

Answer 4

I had to Google the formula for projection.
I couldn't quite remember how to derive it.
So something like this:\[\Large\rm proj_wv=\frac{(\vec w\cdot\vec v)}{|w|^2}*\vec w\]Yes?

Answer 5

Yes they give me that formula but don't show me how to find lwl?

Answer 6

Think of it as a triangle.
The magnitude is the length of the vector.