Use a graphing calculator to approximate to three decimal places the interval(s) where the function is decreasing. Use (open) interval notation. $$y = 0.2 x^5 - 0.49 x^4 - 7.9228 x^3 - 1.96 x^2 - 51.537 x + 3.36$$

Answer =
Note: If the answer involves more than one interval, write them separated by the union symbol, U. If needed, enter $\infty$ as infinity and $-\infty$ as - infinity .