27. Write an expression for the perimeter of the figure as the sum of the lengths of its sides. Then simplify your answer.

What basic trigonometric identity would you use to verify that sin x cos x tan x =1-cos^(2)x?

What values of x satisfy the inequality x^2-9x< 0? how is your answer shown on the graph?

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.