Question

[Nguyễn Tiến Đạt]

tim tap xac dinh:\(y=\sqrt{\dfrac{2cosx+3}{sinx+1}}\)

Answer 1

[Dưa Hấu]

Answer 2

[Trần Ái Linh]

y xác định \(\Leftrightarrow\left\{{}\begin{matrix}\dfrac{2cosx+3}{sinx+1}\ge0\left(1\right)\\sinx+1\ne0\left(2\right)\end{matrix}\right.\)

`(1) <=> 2cosx+3>=sinx+1`

`<=>2cosx+2>=sinx `

Vì `2cosx+2>sin^2x+cos^2x>=sinx`

`=> 2cosx+2>=sinx forall x`

`(2) <=> x \ne -π/2 +k2π`

Vậy `D=RR \\ {-π/2 + k2π} (k \in ZZ)`.