9000086705
Level:
A
Identify the optimal substitution which simplifies the following equation as much as
possible.
\[
2\cos (3x + 33^{\circ }) = -\sqrt{2}
\]
\(3x + 33^{\circ } = t\)
\(\sin 3x = t\)
\(3x = t\)
\(3x + 33^{\circ } = -\sqrt{2}\)
A
9000085601
Level:
A
Evaluate the following numbers and round to the nearest tens.
\[
10^{2} + 11^{2} + 12^{2} + 13^{2} + 14^{2}
\]
\(730\)
\(720\)
\(740\)
\(750\)
9000086706
Level:
A
Identify the equation which arises from the following equation using an optimal
substitution.
\[
2\cos ^{2}x - 7\cos x + 3 = 0
\]
\(2t^{2} - 7t + 3 = 0\)
\(2t^{2} = \frac{3}
{7}\)
\(\cos t = 0\)
\(7\cos t = 3\)
9000085607
Level:
A
Given numbers \(8\: 175\)
and \(3\: 926\),
find the difference between the sum of these numbers rounded to the nearest tens and the sum of these numbers rounded to the nearest hundreds.
\(10\)
\(20\)
\(100\)
\(0\)
9000086707
Level:
A
Identify the equation which arises from the following equation using an optimal
substitution.
\[
\mathop{\mathrm{tg}}\nolimits ^{2}y - 2\mathop{\mathrm{tg}}\nolimits y = 3
\]
\(t^{2} - 2t - 3 = 0\)
\(\mathop{\mathrm{tg}}\nolimits t = \frac{3}
{2}\)
\(t^{2} = \frac{3}
{2}\)
\(\mathop{\mathrm{tg}}\nolimits t = 3\)
9000085608
Level:
A
Given numbers \(456\: 138\)
and \(321\: 814\),
find the difference between the sum of these numbers rounded to the nearest tens and the sum of these numbers rounded to the nearest hundreds.
\(50\)
\(100\)
\(1\: 000\)
\(0\)
9000086708
Level:
A
Identify the equation which arises from the following equation using an optimal
substitution.
\[
\mathop{\mathrm{tg}}\nolimits ^{2}v -\mathop{\mathrm{cotg}}\nolimits ^{-1}v = 2
\]
\(t^{2} - t - 2 = 0\)
Equation is not convenient for a substitution.
\(t^{2} + t = 0\)
\(\mathop{\mathrm{tg}}\nolimits t = 2\)
9000083702
Level:
A
Find all the values of \(x\in \mathbb{R}\)
for which the given expression equals zero.
\[
\frac{x^{2} + 6x + 9}
{x^{2} - 9}
\]
The expression never equals zero.
\(x =\pm 3\)
\(x = 3\)
\(x = -3\)
9000083703
Level:
A
Find all the values of \(x\in \mathbb{R}\)
for which the given expression equals zero.
\[
\frac{x^{3} - x}
{x - 1}
\]
\(x = -1,\ x = 0\)
\(x = 0\)
\(x = 1\)
\(x = -1,\ x = 0,\ x = 1\)
9000083704
Level:
A
Find all the values of \(x\in \mathbb{R}\)
for which the given expression equals zero.
\[
\frac{x^{2} - 4x + 4}
{x(x - 2)}
\]
The expression never equals zero.
\(x = 0\)
\(x = 2\)
\(x = -2,\ x = 0\)