Now, the dot product of N and (0,0,1) should be the cosine of the angle between the two vectors. Formulas for both the dot and cross product of 3d vectors are easily found.

Percentage of annual decline formula in action Let's say a company's revenue declined from $15 million to $10 million over a two-year period. We want to calculate the percentage of annual decline.

Calculating a company's financial variance can help with planning and budgeting in the future.