Problem 3. (1 point) For what value of the constant c is the function f continuous on the interval (-90, co). f ( x ) = 12 - 3, *50 Problem 8. (1 point) 8 - 19, *>c Evaluate the following limit. lim 1- 212+ 2 Answer. Problem 9. (1 point) Problem 12. (1 point) Suppose f is a function which satisfies the properties: For what value(s) of x does the graph of f(x) = 10x - 15x-180x-30 f ( xty)= f(x)+f()+xx+12 have a horizontal tangent? for all real numbers x and y, and help (numbers) Answer(s) submitted; lim f (x ) (incorrect) Problem 13. (1 point) f'( x) = Let f (x) = (413 + 7x+2)(2r# + 5.x -8). Find the requested de- rivative. (12) (x)=