I need this Done someone help please

Define multiplicative inverse. give an example of a number and its multiplicative inverse.

If value of cos330° is √3/2 then find tan165°.

This is a map of the mars exploration rover opportunity predicted landing site on mars. the scale is 1cm : 9.4km. what are the approximate measures of the actual length and width of the ellipse? i mostly need to know how to set it up : )