High school mathematics evaluation field y = √ x + √ (3-3x)

High school mathematics evaluation field y = √ x + √ (3-3x)

So let x = (sin θ) & sup2;, 0 °≤ θ ≤ 90 °
∴y=sinθ+√3cosθ=2sin(θ+60°).
∵0°≤θ≤90°,∴60°≤θ+60°≤150°,
∴1≤2sin(θ+60°)≤2,
Range [1,2]