1003019901
Level:
A
Find the solution of the equation.
\[
\sqrt{-3x^2+2x+5}=3
\]
\(x\in\emptyset\)
\(x\in[-2;2]\)
\(x\in\{-2;2\}\)
\(x\in\mathbb{R}\)
Radical Equations and Inequalities
9000034903
Level:
A
Find all \(x\in \mathbb{R}\)
for which the following expression is undefined.
\[
\sqrt{\left (3x + 4 \right ) \left (\frac{1}
{5} - x\right )}
\]
\(\left (-\infty ;-\frac{4}
{3}\right )\cup \left (\frac{1}
{5};\infty \right )\)
\(\left [ -\frac{4}
{3}; \frac{1}
{5}\right ] \)
\(\left (-\infty ;-\frac{4}
{3}\right ] \cup \left [ \frac{1}
{5};\infty \right )\)
\(\left (-\frac{4}
{3}; \frac{1}
{5}\right )\)
9000034901
Level:
A
Find the domain of the following expression.
\[
\sqrt{\left (2x - 3 \right ) \left (3x + 1 \right )}
\]
\(\left (-\infty ;-\frac{1}
{3}\right ] \cup \left [ \frac{3}
{2};\infty \right )\)
\(\left [ -\frac{1}
{3}; \frac{3}
{2}\right ] \)
\(\left (-\frac{1}
{3}; \frac{3}
{2}\right )\)
\(\left (-\infty ;-\frac{1}
{3}\right )\cup \left (\frac{3}
{2};\infty \right )\)
9000033702
Level:
A
Find the domain of the following expression.
\[
\sqrt{-x^{2 } + 7x - 12} -\frac{1}
{x}
\]
\([ 3;4] \)
\(\mathbb{R}\setminus \left \{0\right \}\)
\(\mathbb{R}\setminus \left \{0;3;4\right \}\)
\(\left (3;4\right )\)
\(\left (-\infty ;3\right )\cup \left (4;\infty \right )\)
\(\left (-\infty ;3] \cup [ 4;\infty \right )\)
9000024809
Level:
B
Find the solution set of the following inequality.
\[
\sqrt{x + 3} > x - 3
\]
\([ -3;6)\)
\( (1;6)\)
\([ -3;3] \)
\( (-\infty ;1)\cup (6;+\infty )\)
9000024810
Level:
C
Find the solution set of the following inequality.
\[
\sqrt{|x|} > x
\]
\(K = (-\infty ;0)\cup (0;1)\)
\(K = (-\infty ;1)\)
\(K =\mathbb{R} ^{+}\)
\(K = (0;1)\)
9000024802
Level:
A
Consider the equation
\[
\sqrt{x^{2 } - 2x + 1} = x + 2
\]
and the equation which arises from this equation by squaring both sides of the
equation, i.e. the equation
\[
\left (\sqrt{x^{2 } - 2x + 1}\right )^{2} = (x + 2)^{2}.
\]
Identify a true statement.
Both equations are equivalent only if
\(x\geq - 2\).
Both equations are equivalent.
Both equations are equivalent only if
\(x\leq - 2\).
None of the above.
9000024803
Level:
A
Removing radical in an equation by squaring both sides may enrich the set of
solutions of this equation and checking the solutions of the new equation in the
original equation may be necessary. Identify a correct conclusion in the particular
case of the following equation.
\[
-\sqrt{x^{2 } - 2x + 1} = x
\]
If we look for the solution in the set
\(\mathbb{R}^{-}\), then
squaring both sides of the equation gives an equivalent equation. The checking of the
solution is not necessary.
If we look for the solution in the set
\(\mathbb{R}^{+}\), then
squaring both sides of the equation gives an equivalent equation. The checking of the
solution is not necessary.
If we look for the solution in the set
\(\mathbb{R}\), then
squaring both sides of the equation gives an equivalent equation. The checking of the
solution is not necessary.
None of the above.
9000024806
Level:
B
In the following list identify the interval which is a subset of the solution set of
the following inequality.
\[
\sqrt{x^{2 } + 2x - 3} > x + 2
\]
\((-\infty ;-3] \)
\(\left (-\frac{7}
{2};+\infty \right )\)
\((1;+\infty )\)
\((-\infty ;-2)\)
9000024807
Level:
C
A body hangs on a string of the length
\(l_{1}\). The length
\(l\) of the spring
defines the period \(T\)
of motion by the relation
\[
T = 2\pi \sqrt{ \frac{l}
{g}},
\]
where \(g\)
is a standard acceleration of gravity. We have to adjust the length of the string such
that the period doubles. Find the new length of the string.
We elongate the string by \(3\cdot l_{1}\),
i.e. \(l_{2} = l_{1} + 3l_{1}\).
The length doubles, i.e. \(l_{2} = 2l_{1}\).
The new length will be half of the original length, i.e.
\(l_{2} = \frac{1}
{2}l_1\).
We shorten the string by \(3\cdot l_{1}\),
i.e. \(l_{2} = l_{1} - 3l_{1}\).