Write the quadratic equation whose roots are 6 and -4 and whose leading coefficient is 4

One expression below in undefined, and the other expression has a well defined value. which expression is undefined and explain why it has no value. which expression is defined? what is the value of that expression and how do you know? what is a different expression using a trig inverse function that is also undefined?

In a graph with several intervals o data how does a constant interval appear? what type of scenario produces a constant interval?

Can someone check if i did this right since i really want to make sure it’s correct. if you do you so much