C

2010016806

Level: 
C
The domain of the expression \( \frac{\cos⁡^2 x}{1+\sin ⁡x} \) is the set:
\( \left\{x\in\mathbb{R}\colon x\neq\frac{3\pi}2 + 2k\pi,\ k\in\mathbb{Z} \right\} \)
\( \mathbb{R}\)
\( \left\{x\in\mathbb{R}\colon x\neq\frac{\pi}2 + 2k\pi,\ k\in\mathbb{Z} \right\} \)
\( \left\{x\in\mathbb{R}\colon x\neq \pi + 2k\pi,\ k\in\mathbb{Z} \right\} \)

2010016404

Level: 
C
Function \( f \) is given completely by the next graph. Identify which of the following statements is true.
\( f(x)=|-\cos x|;\ x\in [ -2\pi;2\pi ]\)
\( f(x)=-|\cos x|;\ x\in [ -2\pi;2\pi ]\)
\( f(x)=|\sin x|;\ x\in [ -2\pi;2\pi ]\)
\( f(x)=-|\sin x|;\ x\in [ -2\pi;2\pi ]\)

2010016114

Level: 
C
Let a point \(B\) be the intersection point of the sphere \(x^2 + y^2 + z^2 + 4x + 2y - 4z - 8 = 0\) and \(y\)-axis. Find the equations of all the tangent planes to the given sphere at the point \(B\).
\(2x -3y -2z -12 = 0\), \(2x + 3y - 2z -6 = 0\)
\(2x + 3y - 2z +12 = 0\), \(2x -3 y -2z +6 = 0\)
\(2x -3y -2z -12 = 0\), \(2x -3 y -2z +6 = 0\)
\(2x + 3y - 2z +12 = 0\), \(2x + 3y - 2z -6 = 0\)