Prove that 1/sin^2A -1/tan^2A= 1

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.

Me! i will mark you brainliest if you are right and show your i don't get polynomials and all the other stuff. multiply and simplify.2x(^2)y(^3)z(^2) · 4xy(^4)x(^2)show your

The height above the ground (in feet) of a ball dropped from the top of a 30-foot-tall building after t seconds is given by the polynomial: ? 16t^2+30 what is the height of the ball after 1/2 second?