HELP I DONT KNOW AND GIVE ME AN EXPLANATION PLZ Explain why the value of [cos θ,sin θ]• [cos(90 + θ),sin(90 + θ)] is independent of θ.

Which is the equation of an ellipse with directrices at x = ±4 and foci at (2, 0) and (−2, 0)?

You eat 8 strawberries and your friend eats 12 strawberries from a bowl. there are 20 strawberries left. which equation and solution give the original number of strawberries?

Fanny mendelssohn manages all the magazines and paperback books at a local grocery store. she prices many paperbacks to sell at $7.99. the cost to the store is $5.29. what is the markup rate on a paperback book, based on its cost?