SOLUTION: x^2-3x-4>0 solve and write in interval notation

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Question 1066507: x^2-3x-4>0 solve and write in interval notation
Found 2 solutions by josgarithmetic, Boreal:
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
x%5E2-3x-4%3E0
%28x-4%29%28x%2B1%29%3E0

system%28x%3C-1%2C++OR%2C+x%3E4%29


(-infinity, -1) OR (4, infinity)

Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
x^2-3x-4=0
(x-4)(x+1)= 0
x= 4
x=-1
-1 and 4 are critical points. They divide the number line into three areas: test less than the smallest, between them, and greater than the largest.
For x <-1 try -2. f(-2) >0
between the two points, try 0 f(0)< 0, does not work
greater than 4, try 5 f(5)=6
(-1, 4)
graph%28300%2C300%2C-10%2C10%2C-10%2C10%2Cx%5E2-3x-4%29