Find all real numbers at which the function f(x)= x^ 2 -9 x^ 2 -4x+3 is not continuous.

MATHEMATICS · Subjective · AP · Calculus AB · Limits and Continuity · Limits and Continuity

Problem

Find all real numbers at which the function

f(x)=\dfrac{x^{2}-9}{x^{2}-4x+3}

is not continuous.