Write the equation of a parabola with the focus at (3,0) and the directrix at x=-3 The answer is y^2 = 12x

Ascientist wants to use a model to present the results of his detailed scientific investigation. why would a model be useful? a )because the model makes the concepts easier to understand b) because the model is easy to put together and to use c) because the model prevents other scientists from asking questions d) because the model requires the audience to pay full attention to it i don't know what to choose because between a and d a is much more likely than d because it only wants to get the attention of the audience. i'm confuse.

Arectangle has a length of 6cm by 8cm what is the length of a diagonal of the rectangle

How much is $1200 worth at the end of1 year,if the interest rate is 5.5% is compounded quarterly.