Mathematics Homework Help

I am having trouble getting to the right answer for this problem. I was already given the answers to the problem, but I just need to know where I am doing wrong when solving?

Question: Using calculus, find the critical points for the function f(x) = e^(x^2+3x-4)-x-1000 and determine if they are a max or a min. (Hint: You may use your calculator to help you solve for x by using the intersect functions of the graph.)

Answer: 

Derivative: e^(x^2+3x-4)(2x+3)-1

Point: (.68520962,-1000.45633986)

My Answer: 

Derivative: e^(x^2+3x-4)(2x+3)-1

I just plugged this in my calculator and got this for the point (minimum).

Point: (.68181818,-.0162305)