The ellipse
\[
5x^{2} + 9y^{2} = 45
\]
has tangent \(2x + 3y = 9\). Find the
values of the real parameter \(k\)
which ensure that the line \(y = kx + 3\)
is a secant for the ellipse.
Satellites travel along approximately circular paths. Consider a satellite in the height
\(h\)
measured from the Earth surface. Further, consider the coordinate system
with origin on the Earth surface directly below the satellite and the
\(y\)-axis oriented up (to
the satellite). The \(x\)-axis
is perpendicular to \(y\)-axis
and it is in the plane defined by the trajectory of the satellite. Neglect the Earth's
rotation and find the equation which describes the path of the satellite. The Earth
radius is \(R\).
The height \(v\)
of a regular hexagonal prism is a double of its side
\(a\). The volume of
the prism is \(648\sqrt{3}\, \mathrm{cm}^{3}\).
Use this information to find the length of the longest solid diagonal in the
prism.
The side of a regular hexagonal prism
\(ABCDEFA'B'C'D'E'F'\) is
\(a = 3\, \mathrm{cm}\) and the height
\(v = 8\, \mathrm{cm}\). Find the length
of the diagonal \(AD'\).
The side of a regular hexagonal prism
\(ABCDEFA'B'C'D'E'F'\) shown in the picture is
\(a = 3\, \mathrm{cm}\) and the height is
\(v = 8\, \mathrm{cm}\). Find the angle
between the diagonal \(AD'\)
and the base plane \(ABC\)
(round your result to the nearest degree).
A body is thrown at the initial angle \(\alpha = 30^{\circ }\)
and the initial velocity \(v_{0} = 20\, \mathrm{m}/\mathrm{s}\).
The trajectory of the body is a part of parabola. Find the directrix of this
parabola. Hint: The coordinates of the moving body as functions of time are
\[
\begin{aligned}x& = v_{0}t\cdot \cos \alpha , &
\\y& = v_{0}t\cdot \sin \alpha -\frac{1}
{2}gt^{2}.
\\ \end{aligned}
\]
Consider the standard acceleration due to gravity
\(g = 10\, \mathrm{m}/\mathrm{s}^{2}\).
The Earth travels around the Sun on an elliptical orbit. The Sun is in the
focus of this ellipse. The maximal distance from Earth to the Sun is
\(152.1\cdot 10^{6}\, \mathrm{km}\), the minimal distance
from Earth to the Sun is \(147.1\cdot 10^{6}\, \mathrm{km}\).
Find the length of the semi-minor axis (one half of the length
of the shorter axis) and round your answer to the nearest
\(10^{4}\, \mathrm{km}\).