Solve: x^2-x-12> 0
opens up (holds water)
find zeros
(x-4)(x+3) = 0
between x = -3 and x = + 4, it is below the x axis (for example try x = 0)
so
x<-3
or
x>+4
find zeros
(x-4)(x+3) = 0
between x = -3 and x = + 4, it is below the x axis (for example try x = 0)
so
x<-3
or
x>+4