Mathematics
Consider the following statements :
1. If f is the subset of Z × Z defined by f = {(xy, x − y); x, y ∈ Z}, then f is a function from Z to Z.
2. If f is the subset of N × N defined by f = {(xy, x + y); x, y ∈ N}, then f is a function from N to N.
Which of the statements given above is/are correct?
Consider the determinant
Δ = $\left|\begin{array}{lll}\text{a}_{11} & \text{a}_{12} & \text{a}_{13} \\ \text{a}_{21} & \text{a}_{22} & \text{a}_{23} \\ \text{a}_{31} & \text{a}_{32} & \text{a}_{33}\end{array}\right|$
If a13 = yz, a23 = zx, a33 = xy and the minors of a13, a23, a33 are respectively (z − y), (z − x), (y − x) then what is the value of Δ ?
If A = $\left(\begin{array}{ccc}1 & 0 & 0 \\ 0 & \cos \theta & \sin \theta \\ 0 & \sin \theta & −\cos \theta\end{array}\right)$, then which of the following are correct?
1. A + adj A is a null matrix
2. A−1 + adj A is a null matrix
3. A − A−1 is a null matrix
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If X is a matrix of order 3 × 3, Y is a matrix of order 2 × 3 and Z is a matrix of order 3 × 2, then which of the following are correct?
1. (ZY)X is a square matrix having 9 entries.
2. Y(XZ) is a square matrix having 4 entries.
3. X(YZ) is not defined.
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Consider the following statements :
1. The set of all irrational numbers between $\sqrt{2}$ and $\sqrt{5}$ is an infinite set.
2. The set of all odd integers less than 100 is a finite set.
Which of the statements given above is/are correct?
Consider the following statements :
1. 2 + 4 + 6 + ........ + 2n = n2 + n
2. The expression n2 + n + 41 always gives a prime number for every natural number n
Which of the above statements is/are correct ?
Let A = {7, 8, 9, 10, 11, 12, 13; 14, 15, 16} and let f ∶ A → N be defined by f(x) = the highest prime factor of x.
How many elements are there in the range of f?
Let R be a relation from N to N defined by R = {(x, y): x, y ∈ N and x2 = y3}. Which of the following are not correct?
1. (x, x) ∈ R for all x ∈ N
2. (x, y) ∈ R ⇒ (y, x) ∈ R
3. (x, y) ∈ R and (y, z) ∈ R ⇒ (x, z) ∈ R
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Consider the following :
1. A ∩ B = A ∩ C ⇒ B = C
2. A ∪ B = A ∪ C ⇒ B = C
Which of the above is/are correct ?
What is the modulus of z?
What is angle θ such that z is purely real ?
where n is an integer
What is angle θ such that z is purely imaginary ?
where n is an integer
What is the value of q if the coefficients of x3 and x6 are equal ?
What is the ratio of the coefficients of middle terms in the expansion (when expanded in ascending powers of x)?
Under what condition the coefficients of x2 and x4 are equal ?
How many 4-letter words each of two vowels and two consonants with or without meaning, can be formed ?
How many 8-letter words with or without meaning, can be formed such that consonants and vowels occupy alternate positions?
How many 8-letter words with or without meaning, can be formed so that all consonants are together?
What is the value of a11C11 + a12C12 + a13C13 ?
What is the value of $\left|\begin{array}{lll}\text{a}_{21} & \text{a}_{31} & \text{a}_{11} \\ \text{a}_{23} & \text{a}_{33} & \text{a}_{13} \\ \text{a}_{22} & \text{a}_{32} & \text{a}_{12}\end{array}\right|$ ?
If $\displaystyle\sum_{x=2}^n$f(x) = 2044, then what is the value of n ?
What is $\displaystyle\sum_{x=1}^5$f(2x − 1) equal to ?
What is $\displaystyle\sum_{x=1}^6$2x f(x) equal to ?
How many received medals in exactly two of the three sports ?
How many received medals in at least two of three sports ?
How many received medals in exactly one of three sports ?
What is P equal to ?
What is Q equal to ?
What is the minimum value of determinant of A ?
What is the height of the lamp post ?
What is $\frac{\text{AB}}{\sin \text{C}}$ equal to ?
What is cos A + cos B + cos C equal to ?
At what height is the top of the tower above the ground level ?
If θ is the inclination of the tower to the horizontal, then what is cot θ equal to ?
What is the length of the tower ?
Consider the following statements in respect of the line passing through origin and inclining at an angle of 75° with the positive direction of x-axis :
1. The line passes through the point $\left(1, \frac{1}{2−\sqrt{3}}\right)$.
2. The line entirely lies in first and third quadrants.
Which of the statements given above is/are correct ?
Consider the points A(2, 4, 6), B(−2, −4, −2), C(4, 6, 4), and D(8, 14, 12). Which of the following statements is/are correct?
1. The points are the vertices of a rectangle ABCD.
2. The mid-point of A C is the same as that of BD.
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Consider the equation of a sphere x2 + y2 + z2 − 4x − 6y − 8z − 16 = 0.
Which of the following statements is/are correct ?
1. z-axis is tangent to the sphere.
2. The centre of the sphere lies on the plane x + y + z − 9 = 0.
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Consider the following statements :
1. The direction ratios of y-axis can be <0, 4, 0>
2. The direction ratios of a line perpendicular to z-axis can be <5, 6, 0>
Which of the statements given above is/are correct?
Let f(x) be a function such that f'(x) = g(x) and f''(x) = −f(x). Let h(x) = {f(x)}2 + {g(x)}2. Then consider the following statements :
1. h'(3) = 0
2. h(1) = h(2)
Which of the statements given above is/are correct ?
Consider the following statements in respect of the function f(x) = $\left\{\begin{array}{rc}|x|+1, & 0<|x| \leqslant 3 \\ 1, & x = 0\end{array}\right.$
1. The function attains maximum value only at x = 3
2. The function attains local minimum only at x = 0
Which of the statements given above is/are correct ?
Consider the following statements:
1. The degree of the differential equation $\frac{\text{dy}}{\text{dx}} + \cos \left(\frac{\text{dy}}{\text{dx}}\right)$ = 0 is 1.
2. The order of the differential equation $\left(\frac{\text{d}^2\text{y}}{\text{dx}^2}\right)^3 + \cos \left(\frac{\text{dy}}{\text{dx}}\right) $ = 0 is 2.
Which of the statements above is/are correct?
Which one of the following subjects shows highest variability of marks ?
What is the coefficient of variation of marks in Mathematics ?
What is the median of the distribution ?
What is mean deviation about the median ?
What is the mean deviation about the mean ?