a)Thay m=1 vào pt ta được:
\(sinx+\sqrt{3}cosx=2\)
\(\Leftrightarrow\dfrac{1}{2}sinx+\dfrac{\sqrt{3}}{2}cosx=1\)
\(\Leftrightarrow sin\left(x+\dfrac{\pi}{3}\right)=1\)
\(\Leftrightarrow x+\dfrac{\pi}{3}=\dfrac{\pi}{2}+k2\pi,k\in Z\)
\(\Leftrightarrow x=\dfrac{\pi}{6}+k2\pi,k\in Z\)
b) Để pt vô ng khi : \(m^2+3< \left(m+1\right)^2\)
\(\Leftrightarrow m>1\)
Vậy ....