the domain of √x is x≥0
the domain of lnx is x > 0
so,
(a) where is w^2-81w+81 positive?
It's a parabola opening up, so it is negative between the roots, and positive elsewhere. So first step, find the roots as normal.
(b) 81w - 5 > 0
(c) -w ≥ 0, so w ≤ 0
Find the domain of 𝒇(𝒘) =
√𝒘𝟐−𝟖𝟏𝒘+𝟖𝟏
𝐥𝐧(𝟖𝟏𝒘−𝟓)
+ √−𝒘.
1 answer