Conics

9000123107

Level: 
C
In the following list identify a line such that the line has a unique intersection with the hyperbola \[ x^{2} - y^{2} = 5 \] but the line is not the tangent to this hyperbola.
\(p\colon \frac{x} {5} + \frac{y} {5} = 1\)
\(p\colon y = 5x\)
\(p\colon 2x + y = 5\)
\(\begin{aligned}[t] p\colon x& = 1 & \\y & = -1 + t\text{; }t\in \mathbb{R} \\ \end{aligned}\)

9000123103

Level: 
C
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.
\(k\in \left (-\infty ;-\frac{2} {3}\right )\cup \left (\frac{2} {3};\infty \right )\)
\(k\in \left [ -\frac{2} {3}; \frac{2} {3}\right ] \)
\(k\in \left (-\frac{2} {3}; \frac{2} {3}\right )\)
\(k\in \left (-\infty ;-\frac{2} {3}\right ] \cup \left [ \frac{2} {3};\infty \right )\)