`u = <-8, 15>` Use the dot product to find the magnitude of u.
The magnitude of a vector `u` is the square root of its product by itself, because
and `theta=0,` `cos(theta)=1.` So
This is the answer.
There's no way to have a dot product, because there is only one vector. A dot product is two vectors multiplied together.
Using the Pythagorean theorem...
`a^2 + b^2= c^2` where a is the x coordinate, b is the y coordinate, and c is the length of the vector.
`sqrt(a^2 + b^2) = c` after taking the square root of both sides.
`sqrt((-8)^2 + (15)²) `
`sqrt(64 + 225) `
17 is the magnitude