Question

Please help!
what is the angle between v=(-7,8) and the positive x-axis? I need to use a formula (which I will write below) to find the cosine of the angle between the two vectors, (-7,8) and (1,0).

Answer 1

You want to draw the picture out.

Answer 2

Yes, please.

Answer 3

Do you understand so far?

Answer 4

\(\textit{angle between two vectors }\\ \quad \\
cos(\theta)=\cfrac{u \cdot v}{||u||\ ||v||} \implies \cfrac{\text{dot product}}{\text{product of magnitudes}}\\ \quad \\
\theta = cos^{-1}\left(\cfrac{u \cdot v}{||u||\ ||v||}\right)\)

Answer 5

It's blank I can't see anything