It is not easy. I have to download the questions myself. The first question of your question requires that B and C need two equations. The title tells us that two real roots can be obtained by solving the equation, and then the analytical formula of the corresponding relationship can be obtained.

The second question should be noted that t is a variable, and the area of a triangle is easy to find, and the base is multiplied by half the height. According to the meaning of the question, list the areas so that you can get the height of the triangle. Note that m is the moving point on the image y2.

The third question has nothing to do with the first two questions. Within the given range. One thing that can be grasped is where the point is and satisfy its analytical formula. Find the answer through its scope.

I won't write if you have the answer. I hope you can understand. If you don't understand, ask your teacher. It would be easier to explain.