Đáp án: `D=\mathbb{R} \ \backslash \ {\frac{3π}{2}+2kπ, k∈\mathbb{Z}}`
Giải:
`y=tan(\frac{x}{2}-\frac{π}{4})`
Đkxđ:
`cos(\frac{x}{2}-\frac{π}{4}) \ne 0`
⇔ `\frac{x}{2}-\frac{π}{4} \ne \frac{π}{2}+kπ`
⇔ `\frac{x}{2} \ne \frac{π}{4}+\frac{π}{2}+kπ`
⇔ `\frac{x}{2} \ne \frac{3π}{4}+kπ`
⇔ `x \ne \frac{3π}{2}+2kπ \ (k∈\mathbb{Z})`
Vậy `D=\mathbb{R} \ \backslash \ {\frac{3π}{2}+2kπ, k∈\mathbb{Z}}`
