NTA JEE Main 22nd July 2021 Shift 1 - Mathematics

Let $$n$$ denote the number of solutions of the equation $$z^2 + 3\bar{z} = 0$$, where $$z$$ is a complex number. Then the value of $$\sum_{k=0}^{\infty} \frac{1}{n^k}$$ is equal to

Let $$S_n$$ denote the sum of first $$n$$-terms of an arithmetic progression. If $$S_{10} = 530$$, $$S_5 = 140$$, then $$S_{20} - S_6$$ is equal to:

The number of solutions of $$\sin^7 x + \cos^7 x = 1$$, $$x \in [0, 4\pi]$$ is equal to

Let the circle $$S : 36x^2 + 36y^2 - 108x + 120y + C = 0$$ be such that it neither intersects nor touches the co-ordinate axes. If the point of intersection of the lines, $$x - 2y = 4$$ and $$2x - y = 5$$ lies inside the circle $$S$$, then:

Let $$E_1 : \frac{x^2}{a^2} + \frac{y^2}{b^2} = 1$$, $$a > b$$. Let $$E_2$$ be another ellipse such that it touches the end points of major axis of $$E_1$$ and the foci of $$E_2$$ are the end points of minor axis of $$E_1$$. If $$E_1$$ and $$E_2$$ have same eccentricities, then its value is:

Let a line $$L : 2x + y = k$$, $$k > 0$$ be a tangent to the hyperbola $$x^2 - y^2 = 3$$. If $$L$$ is also a tangent to the parabola $$y^2 = \alpha x$$, then $$\alpha$$ is equal to:

Which of the following Boolean expressions is not a tautology?

Let $$A = [a_{ij}]$$ be a real matrix of order $$3 \times 3$$, such that $$a_{i1} + a_{i2} + a_{i3} = 1$$, for $$i = 1, 2, 3$$. Then, the sum of all entries of the matrix $$A^3$$ is equal to:

The values of $$\lambda$$ and $$\mu$$ such that the system of equations $$x + y + z = 6$$, $$3x + 5y + 5z = 26$$ and $$x + 2y + \lambda z = \mu$$ has no solution, are:

Let $$[x]$$ denote the greatest integer less than or equal to $$x$$. Then, the values of $$x \in R$$ satisfying the equation $$[e^x]^2 + [e^x + 1] - 3 = 0$$ lie in the interval:

If the domain of the function $$f(x) = \frac{\cos^{-1}\sqrt{x^2 - x + 1}}{\sqrt{\sin^{-1}\left(\frac{2x-1}{2}\right)}}$$ is the interval $$(\alpha, \beta]$$, then $$\alpha + \beta$$ is equal to:

Let $$f : R \to R$$ be defined as $$f(x) = \begin{cases} \frac{x^3}{(1-\cos 2x)^2} \log_e\left(\frac{1+2xe^{-2x}}{(1-xe^{-x})^2}\right), & x \neq 0 \\ \alpha, & x = 0 \end{cases}$$
If $$f$$ is continuous at $$x = 0$$, then $$\alpha$$ is equal to:

Let $$f : R \to R$$ be defined as $$f(x) = \begin{cases} -\frac{4}{3}x^3 + 2x^2 + 3x, & x > 0 \\ 3xe^x, & x \le 0 \end{cases}$$
Then $$f$$ is increasing function in the interval

If $$\int_0^{100\alpha} \frac{\sin^2 x}{e^{\left(\frac{x}{\pi} - \left[\frac{x}{\pi}\right]\right)}} dx = \frac{\alpha\pi^3}{1+4\pi^2}$$, $$\alpha \in R$$ where $$[x]$$ is the greatest integer less than or equal to $$x$$, then the value of $$\alpha$$ is:

Let $$y = y(x)$$ be the solution of the differential equation $$\cosec^2 x \, dy + 2dx = (1 + y\cos 2x) \cosec^2 x \, dx$$, with $$y\left(\frac{\pi}{4}\right) = 0$$. Then, the value of $$(y(0) + 1)^2$$ is equal to:

Let a vector $$\vec{a}$$ be coplanar with vectors $$\vec{b} = 2\hat{i} + \hat{j} + \hat{k}$$ and $$\vec{c} = \hat{i} - \hat{j} + \hat{k}$$. If $$\vec{a}$$ is perpendicular to $$\vec{d} = 3\hat{i} + 2\hat{j} + 6\hat{k}$$, and $$|\vec{a}| = \sqrt{10}$$. Then a possible value of $$[\vec{a} \ \vec{b} \ \vec{c}] + [\vec{a} \ \vec{b} \ \vec{d}] + [\vec{a} \ \vec{c} \ \vec{d}]$$ is equal to:

Let three vectors $$\vec{a}, \vec{b}$$ and $$\vec{c}$$ be such that $$\vec{a} \times \vec{b} = \vec{c}$$, $$\vec{b} \times \vec{c} = \vec{a}$$ and $$|\vec{a}| = 2$$. Then which one of the following is not true?

Let $$L$$ be the line of intersection of planes $$\vec{r} \cdot (\hat{i} - \hat{j} + 2\hat{k}) = 2$$ and $$\vec{r} \cdot (2\hat{i} + \hat{j} - \hat{k}) = 2$$. If $$P(\alpha, \beta, \gamma)$$ is the foot of perpendicular on $$L$$ from the point $$(1, 2, 0)$$, then the value of $$35(\alpha + \beta + \gamma)$$ is equal to:

If the shortest distance between the straight lines $$3(x-1) = 6(y-2) = 2(z-1)$$ and $$4(x-2) = 2(y-\lambda) = (z-3)$$, $$\lambda \in R$$ is $$\frac{1}{\sqrt{38}}$$, then the integral value of $$\lambda$$ is equal to:

Four dice are thrown simultaneously and the numbers shown on these dice are recorded in $$2 \times 2$$ matrices. The probability that such formed matrices have all different entries and are non-singular, is:

If the digits are not allowed to repeat in any number formed by using the digits 0, 2, 4, 6, 8, then the number of all numbers greater than 10,000 is equal to ___.

The sum of all the elements in the set $$\{n \in \{1, 2, \ldots, 100\} | \text{H.C.F. of } n \text{ and } 2040 \text{ is } 1\}$$ is equal to ___.

If the constant term, in binomial expansion of $$\left(2x^r + \frac{1}{x^2}\right)^{10}$$ is 180, then $$r$$ is equal to ___.

The number of elements in the set $$\{n \in \{1, 2, 3, \ldots, 100\} | (11)^n > (10)^n + (9)^n\}$$ is ___.

Consider the following frequency distribution:

If mean = $$\frac{309}{22}$$ and median = 14, then the value $$(a-b)^2$$ is equal to ___.

Let $$A = \begin{bmatrix} 0 & 1 & 0 \\ 1 & 0 & 0 \\ 0 & 0 & 1 \end{bmatrix}$$. Then the number of $$3 \times 3$$ matrices $$B$$ with entries from the set $$\{1, 2, 3, 4, 5\}$$ and satisfying $$AB = BA$$ is ___.

Let $$A = \{0, 1, 2, 3, 4, 5, 6, 7\}$$. Then the number of bijective functions $$f : A \to A$$ such that $$f(1) + f(2) = 3 - f(3)$$ is equal to ___.

Let $$f : R \to R$$ be a function defined as $$f(x) = \begin{cases} 3\left(1 - \frac{|x|}{2}\right) & \text{if } |x| \le 2 \\ 0 & \text{if } |x| > 2 \end{cases}$$
Let $$g : R \to R$$ be given by $$g(x) = f(x+2) - f(x-2)$$. If $$n$$ and $$m$$ denote the number of points in $$R$$ where $$g$$ is not continuous and not differentiable, respectively, then $$n + m$$ is equal to ___.

The area (in sq. units) of the region bounded by the curves $$x^2 + 2y - 1 = 0$$, $$y^2 + 4x - 4 = 0$$ and $$y^2 - 4x - 4 = 0$$ in the upper half plane is ___.

Let $$y = y(x)$$ be the solution of the differential equation $$\left((x+2)e^{\left(\frac{y+1}{x+2}\right)} + (y+1)\right)dx = (x+2)dy$$, $$y(1) = 1$$. If the domain of $$y = y(x)$$ is an open interval $$(\alpha, \beta)$$, then $$|\alpha + \beta|$$ is equal to ___.