1
WB JEE 2026
MCQ (Single Correct Answer)
+1
-0.25
Change Language

The expression $\sum_{k=1}^{32}(3 K+2)\left\{\sum_{r=1}^{10}\left(\sin \frac{2 r \pi}{11}-i \cos \frac{2 r \pi}{11}\right)\right\}^k$ represents

A

$48(1+\mathrm{i})$

B

$-48(1-\mathrm{i})$

C

$-\frac{48}{11}(1-\mathrm{i})$

D

$48(1-\mathrm{i})$

2
WB JEE 2026
MCQ (Single Correct Answer)
+1
-0.25
Change Language

$\theta$ elimination from the equation $x^2+y^2=\frac{x \cos 3 \theta+y \sin 3 \theta}{\cos ^3 \theta}=\frac{y \cos 3 \theta-x \sin 3 \theta}{\sin ^3 \theta}$ will be

A

$4\left(x^4+y^4\right)=3 x+4 y$

B

$\left(x^2+y^2+2 x\right)\left(x^2+y^2-x\right)=2 y^2$

C

$\left(x^2+y^2-2 x\right)\left(x^2+y^2+x\right)=9 y$

D

$x^{2 / 3}+y^{2 / 3}=1$

3
WB JEE 2026
MCQ (Single Correct Answer)
+1
-0.25
Change Language

If $t_n$ denotes the $n^{\text {th }}$ term of an A.P. and $t_p=\frac{1}{q}, t_q=\frac{1}{p}$, then which one of the following options is a root of the equation $(p+2 q-3 r) x^2+(q+2 x-3 p) x+(r+2 p-3 q)=0 ?$

A

$t_{p q}$

B

$t_q$

C

$t_p$

D

$t_{p+q}$

4
WB JEE 2026
MCQ (Single Correct Answer)
+1
-0.25
Change Language

Consider the sequence of numbers $(1,2,3, \ldots \ldots, 13)$. A person choose three numbers at random from the sequence. The probability that the chosen three number form an A.P. is

A

$\frac{21}{157}$

B

$\frac{18}{143}$

C

$\frac{29}{180}$

D

$\frac{24}{163}$