1
WB JEE 2026
MCQ (Single Correct Answer)
+2
-0.5
Change Language

Let $Z_1, Z_2$ be the roots of the equation $Z^2+p Z+q=0$, where the coefficients $p$ and $q$ may be complex numbers and also let $A, B$ represent $Z_1, Z_2$ respectively in the complex plane. If $\angle A O B=\alpha \neq 0$ and $O A=O B$, where $O$ is the origin, then the value of $\frac{p^2}{q} \sec ^2 \frac{\alpha}{2}$ will be

A

$\frac{1}{4}$

B

$\frac{3}{4}$

C

4

D

1

2
WB JEE 2026
MCQ (Single Correct Answer)
+2
-0.5
Change Language

Let $g(x)=a x+b$, where $a<0$ and $g$ is defined from $[1,3]$ onto $[0,2]$. Then the value of $\cot \left(\cos ^{-1}(|\sin x|+|\cos x|)+\right. \left.\sin ^{-1}(-|\cos x|-|\sin x|)\right)$ is equal to

A

$\mathrm{g}(2)+\mathrm{g}(3)$

B

$\mathrm{g}(2)$

C

$\mathrm{g}(3)$

D

$g(1)+g(2)$

3
WB JEE 2026
MCQ (Single Correct Answer)
+2
-0
Change Language

If $\sum_{r=0}^{2 n} a_r(x-2)^r=\sum_{r=0}^{2 n} b_r(x-3)^r$ and $a_k=1 \forall k \geq 1$, then the value of $\frac{b_n}{{ }^{2 n+1} C_{n+1}}$ is

A

$\frac{1}{2}$

B

2

C

$\frac{1}{4}$

D

1

4
WB JEE 2026
MCQ (Single Correct Answer)
+2
-0
Change Language

If $f(x)$ is differentiable for all $x \in \mathbb{R}$ and satisfies the relation

$x=\mathop {\lim }\limits_{n \to \infty }\frac{\left[1^2(f(x))^x\right]+\left[2^2(f(x))^x\right]+\ldots+\left[n^2(f(x))^x\right]}{n^3}$ where [.] denotes the greatest integer function, then $f^{\prime}(x)=$

A

$\frac{1}{3 x^2} \log x$

B

$3 x^{\frac{1}{x}}(1-\log 3 x)$

C

$(3 x)^{\frac{1}{x}}\left[\frac{1-\log 3 x}{x^2}\right]$

D

$(3 x)^{\frac{1}{x}}\left[\frac{\log 3 x-1}{x^2}\right]$