Systems of nonlinear equations and inequalities

9000020904

Level: 
C
Determine all the values of the parameter \(c\in \mathbb{R}\) so that the following system has two solutions in \(\mathbb{R}\times \mathbb{R}\). \[ \begin{alignedat}{80} &x^{2} & + &y^{2} & = 2 & & & & & & \\ &x & + &c & = y & & & & & & \\\end{alignedat}\]
\(|c| < 2\)
\(|c| = 2\)
\(|c| > 2\)
\(c = 2\)

9000020905

Level: 
C
Find the condition on the parameter \(c\in \mathbb{R}\) which ensures that the following system has a unique solution in \(\mathbb{R}\times \mathbb{R}\). \[ \begin{alignedat}{80} &x^{2} & + &y^{2} & = 2 & & & & & & \\ &x & + &c & = y & & & & & & \\\end{alignedat}\]
\(|c| = 2\)
\(|c| > 2\)
\(|c| < 2\)
\(c = 2\)

9000020906

Level: 
A
Identify an equation which can be obtained from the following system by eliminating one of the variables. \[ \begin{alignedat}{80} &y^{2} & - &2 &x & + &3 & = 0 & & & & & & & & \\ &x & - & &y & - &1 & = 0 & & & & & & & & \\\end{alignedat}\]
\((y - 1)^{2} = 0\)
\((y + 1)^{2} = 0\)
\((x - 4)^{2} = 0\)
\((x + 2)^{2} = 0\)

9000020907

Level: 
B
Identify a true statement related to the solution of the following system in \(\mathbb{R}\times \mathbb{R}\). \[ \begin{alignedat}{80} &2x^{2} & - & &y^{2} & - &2 &x & - 5 & = 0 & & & & & & & & & & \\ & & & &3x & - & &y & - 5 & = 0 & & & & & & & & & & \\\end{alignedat}\]
The system has no solution.
The system has two solutions.
The system has a unique solution.
None of the above conclusions can be obtained.

9000020903

Level: 
B
Identify a true statement related to the solution of the following system in \(\mathbb{R}\times \mathbb{R}\). \[ \begin{alignedat}{80} &x^{2} & + &4 & &y^{2} & - & &2x & = &15 & & & & & & & & & & & & \\ &x & - & & &y & + & &1 & = &0 & & & & & & & & & & & & \\\end{alignedat}\]
The system has two solutions.
The system has a unique solution.
The system does not have any solution.
The system has infinitely many solutions.

9000020908

Level: 
C
Assuming that the real parameter \(c\) satisfies \(c > 16\), solve the system and identify a true statement. \[ \begin{alignedat}{80} &y^{2} & - &4x & & = 0 & & & & & & \\8 &x & - &4y & + c & = 0 & & & & & & \\\end{alignedat}\]
The system has no solution.
The system has two solutions.
The system has a unique solution.
The system has infinitely many solutions.

9000009909

Level: 
C
Consider the system \[\begin{aligned} y & = \frac{k} {x}, & & \\y & = a, & & \end{aligned}\] where \(a\), \(k\) are real parameters and \(x\), \(y\) are real variables. Determine the conditions for \(a\) and \(k\) so that the system has a unique solution in \(\mathbb{R}^{-}\times \mathbb{R}^{-}\).
\(a < 0\) and \(k > 0\)
\(a < 0\) and \(k < 0\)
\(a > 0\) and \(k < 0\)
\(a > 0\) and \(k > 0\)