Question

Какая из функций имеет область определения промежуток [-4;4)?

Answer 1

$y=\frac{x}{x-4}+\sqrt{16-x^2}\\\\OOF:\; \; \left \{ {{x-4\ne 0} \atop {x^2-16\geq 0}} \right. \; \left \{ {{x\ne 4\qquad } \atop {(4-x)(4+x)\geq 0}} \right. \; \left \{ {{x\ne 4} \atop {(x-4)(x+4)\leq 0}} \right. \; \left \{ {{x\ne 4} \atop {x\in [-4,4\, ]}} \right. \; \Rightarrow \; \; \boxed {x\in [-4,4)}\\\\\\(x-4)(x+4)\leq 0:\quad +++[-4\, ]---[\, 4\, ]+++$