Signs of Trigonometric Functions II Submitted by ladislav.foltyn on Fri, 04/19/2019 - 16:56 Question: In each row, check the cell whenever the corresponding function takes a positive value.
Signs of the Trigonometric Functions I Submitted by ladislav.foltyn on Thu, 04/18/2019 - 10:45 Question: In each row, check the cell whenever the corresponding function takes a positive value.
Evaluating Expressions with Trigonometric Functions I Submitted by ladislav.foltyn on Sat, 02/23/2019 - 13:12
1003076712 Level: CLet \( \sin x = a \) and \( \cos x = b \). Then \( \cos(2x) \) is equal to:\( b^2-a^2 \)\( 2b \)\( 2ab \)\( a^2-b^2 \)
1003076711 Level: C\( ABC \) is a triangle with side \( c = 27\,\mathrm{cm} \) and the angle \( \gamma = 78^{\circ} \). The radius of the circle circumscribed is:\( 13.8\,\mathrm{cm} \)\( 27.6\,\mathrm{cm} \)\( 18.3\,\mathrm{cm} \)\( 6.9\,\mathrm{cm} \)
1003076709 Level: CThe area of an obtuse triangle is \( 2\,\mathrm{dm}^2 \). The lengths of sides containing the obtuse angle are \( 2\,\mathrm{dm} \) and \( 4\,\mathrm{dm} \). The measure of this angle is:\( 150^{\circ} \)\( 165^{\circ} \)\( 155^{\circ} \)\( 158^{\circ} \)
1003076707 Level: BHow many values of the angle \( \alpha \in\left[0^{\circ}; 360^{\circ}\right] \) satisfy the equation \( \sin \alpha = \cos\alpha \)?\( 2 \)\( 1 \)\( 0 \)\( 3 \)