Question

Giải giúp

 

Answer 1

Vì \(sin\alpha=\dfrac{\sqrt{3}}{2}\Rightarrow\alpha=60\)

\(\Rightarrow cos\alpha=cos60=\dfrac{1}{2}\)

\(tan\alpha=tan60=\sqrt{3}\)

\(cot\alpha=cot60=\dfrac{1}{\sqrt{3}}\)

 

Answer 2

Ta có: \(\sin^2\alpha+\cos^2\alpha=1\)

\(\Leftrightarrow\cos^2\alpha=1-\dfrac{3}{4}=\dfrac{1}{4}\)

hay \(\cos\alpha=\dfrac{1}{2}\)

Ta có: \(\tan\alpha=\dfrac{\sin\alpha}{\cos\alpha}\)

nên \(\tan\alpha=\dfrac{\sqrt{3}}{2}:\dfrac{1}{2}=\sqrt{3}\)

Ta có: \(\cot\alpha=\dfrac{1}{\tan\alpha}\)

nên \(\cot\alpha=\dfrac{1}{\sqrt{3}}=\dfrac{\sqrt{3}}{3}\)