Choose the most appropriate options. If the SD of a set of observations is 8 and each observation is divided by -2, then the SD of the new set of observation will be:
Choose the most appropriate option. On the sphere \( (x - 1)^2 + (y + 2)^2 + (z - 3)^2 = 25 \), find the point \( M_0 \) to the plane \( 3x - 4z + 19 \).
\[ \lim_{x \to 0} \frac{\ln \cos 2x}{\sin 2x} \]
Choose the most appropriate options. Let \( f(x) = ax^3 + 5x^2 - bx + 1 \). If when divided by \( x - 1 \) it leaves a remainder of 5, and \( f(x) \) is divisible by \( 3x - 1 \), then
$ (1 + 2i)^6 $ is equal to: