Graph the polynomial in the given viewing rectangle. Find the coordinates of all local extrema. State each answer correct to two decimal places. (If an answer does not exist, enter DNE.)

y = 2x3 − 3x2 − 12x − 32, [ −5, 5] by [−60, 30]
find minimum
find maximum

2 answers

You will have to do this graphically, since it's an algebra problem. There are lots of online graphing utilities. A good one is

http://rechneronline.de/function-graphs/

You can set the domain and range and the grid resolution. Reading off the extrema will be easy.
ax+4 -7=0 (1,-2) and (-6,3)