Question

What is the domain of f in the equation
F(x)=5/x2-18x+45

Answer 1

`f(x)=(5)/(x^2-18x+45)\\\\The\ domain:\\\\x^2-18x+45\\eq0\\\\x^2-15x-3x+45\\eq0\\\\x(x-15)-3(x-15)\\eq0\\\\(x-15)(x-3)\\eq0\iff x-15\\eq0\ \wedge\ x-3\\eq0\\\\\boxed{x\\eq15\ \wedge\ x\\eq3}\to\boxed{x\in\mathbb{R}-\{3,\ 15\}}`