Should be tan positive 30
Slope of a line parallel is equal to change in y over change in x: which is 9/8, or 1.125. A line perpendicular is the negative reciprocal, which is -8/9.
The coefficients of x4 is 9. It has factors of 1, 3, and 9. The constant is 4. It has factors of 1, 2, and 4.
The (positive and negative) ratios of the factors of the coefficient of the x4 and the constant 4 are the potential rational roots of the function.
The answers are:
1, -1, 3, -3, 9, -9, 1/2, -1/2, 3/2, -3/2, 3/4, -3/4, 9/2, -9/2, 9/4, -9/4
The scale factor of the length of the sides of the cubes is 2:3