Câu hỏi:

\[\cot \alpha = \frac{4}{3}\];

\[\sin \alpha = \frac{3}{5}\];

\[\tan \alpha = \frac{4}{5}\]

\[\sin \alpha = - \frac{3}{5}\]

A. sin(α) > 0; cos(α) > 0;

B. sin(α) > 0; cos(α) < 0;

C. sin(α) < 0; cos(α) > 0;

D. sin(α) < 0; cos(α) < 0

A. 1;

B. – 1;

C. 0;

D. Không xác định

A. 5;

B. \(\frac{5}{3}\);

C. 7;

C. 7;

D.\(\frac{7}{3}\)

\(\cos 750^\circ = \frac{{\sqrt 3 }}{2}\);

\(\sin 1320^\circ = - \frac{{\sqrt 3 }}{2}\);

\(\cot 1200^\circ = \frac{{\sqrt 3 }}{3}\);

\(\tan 690^\circ = - \frac{{\sqrt 3 }}{3}\)

A. \(\frac{2}{7}\);

B. \(\frac{1}{7}\);

C. \(\frac{{5 - \sqrt 6 }}{{6 + \sqrt 3 }}\);

D. \(\frac{7}{{13}}\)

A. 60°;

B. 45°;

C. 30°;

D. 120°

A. \(\frac{{a\sqrt 2 }}{2}\);

B. \(a\sqrt 2 \);

C. \(\frac{{a\sqrt 3 }}{2}\);

D. \(a\sqrt 3 \)

A. 1;

B. – 1;

C. 0;

D. \(\frac{1}{2}\).

A. 1;

B. – 1;

C. \(\frac{1}{4}\);

D. \( - \frac{1}{4}\).