A.\(\frac{{{\pi ^2}}}{{36}} - \frac{{\pi \sqrt 3 }}{3} + \ln 2\).     
B.\(\frac{{4{\pi ^2}}}{9} - \frac{{\pi \sqrt 3 }}{3} - \ln 2\).
C.\(\frac{{4{\pi ^2}}}{9} - \frac{{\pi \sqrt 3 }}{3} + \ln 2\) .
D.\(\frac{{{\pi ^2}}}{{36}} - \frac{{\pi \sqrt 3 }}{3} - \ln 2\).

A.\(5\sqrt 3 .\)
B.\(\sqrt {41} .\)
C.\(\sqrt {61} .\)
D.\(3\sqrt 5 .\)

A.2
B.4
C.3
D.1

A.\(z = 1 + 2i.\)
B.\(z = 1 - 2i.\)
C.\(z = 2 - i.\)
D.\(z =  - 1 - 2i.\)

A.\({S_{tp}} = 21\pi \)
B.\({S_{tp}} = 24\pi \)
C.\({S_{tp}} = 18\pi \)
D.\({S_{tp}} = 30\pi \)

A.9
B.\(5\) .
C.\(1\) .
D.\( - 1\).

A.\(\frac{1}{2}\).
B.\(\frac{3}{2}\).
C.\(1\) .
D.\(2\)  .

A.\(4{a^3}.\)
B.\(16{a^3}.\)
C.\(\frac{8}{3}{a^3}.\)
D.\(8{a^3}.\)

A.\(\frac{{\pi .{a^3}}}{4}\).
B.\(\frac{{\pi .{a^3}}}{3}\).
C.\(\frac{{\pi .{a^3}}}{{12}}\).
D.\(\pi {a^3}\).

A.\(\frac{{8\pi {a^3}}}{3}\)
B.\(\frac{{8\sqrt 2 \pi {a^3}}}{3}\)
C.\(\frac{{4\pi {a^3}}}{3}\)
D.\(\frac{{4\sqrt 2 \pi {a^3}}}{3}\)