Find all values of x such that x(x+7.5)>38.5 . Answer with interval notation.
+36916 Expand to x^2+7.5x - 38.5 > 0 Use quadratic formula to find x = -11 and 3.5
These are the zeros of a normally upright parabola.....so x outside of these numbers, the fxn would be > 0
BETWEEN ( & including the values) the values of the function are zero or negative
so -11 >x>3.5
+1253 EP is right except in Interval Notation it is
(-11, 3.5), thanks EP
You are very welcome!
:P
+36916 Thanx for pointing that out ! 
BUT ACTUALLY, we need interval notation with a disjunction....
it should look like this:
(-inf, -11) U (3.5, +inf)
Sorry for the confusion !
