Find the domain of fx x1x3 9xSolutionThe denomination of t

Solution

The denomination of the expression defining f(x) is x³ -9x = x(x²-9)= x(x+3)(x-3).Since division by 0 is not defined, hence the domain of f(x) = (x+1)/( x³ -9x) is { x R: x -3, x0 and x3}.