Question(s) from Search: IIT

Let f(x) be differentiable on the interval (0, ∞) such that f (1) = 1 and  for each x > 0. Then f(x) is

a)

b)

c)

d)

If y = y(x) satisfies the differential equation $8\sqrt{x}\sqrt{9+\sqrt{x}}\mathrm{dy}={\left(\sqrt{4+\sqrt{9+\sqrt{x}}}\right)}^{-1}\mathrm{dx},x>0$

and $y\left(0\right)=\sqrt{7}$ Then y(256) =

a) 16

b) 3

c) 9

d) 80

A lot contains 20 articles. The probability that the lot contains exactly 2 defective articles is 0.4 and the probability that the lot contains exactly three defective articles is 0.6. Articles are drawn from the lot at random one by one without replacement and tested till defective articles are found. What is the probability that the testing will end at the 12^th testing?

If the curve y = f(x) passes through the point (1, −1) and satisfies the differential equation y(1 + xy) dx = xdy then $f\left(\frac{-1}{2}\right)$

is equal to

a) $\frac{-2}{5}$

b) $\frac{-4}{5}$

c) $\frac{2}{5}$

d) $\frac{4}{5}$

One or more than one correct options

Let f : (0, ∞) → ℝ be a differentiable function such that $f^{\prime }\left(x\right)=2-\frac{f(x)}{x}$

for all x ∈ (0, ∞) and f(1) ≠ 1. Then

a) $\underset{x\to 0^{+}{f}^{\prime }\left(\frac{1}{x}\right)=1}{\lim }$

b) $\underset{x\to 0^{+}x{f}^{\prime }\left(\frac{1}{x}\right)=2}{\lim }$

c) $\underset{x\to 0^{+}{x^{2}f}^{\prime }x=0}{\lim }$

d) $\left|f\left(x\right)\right|\le 2\mathrm{for}\mathrm{all}x\in (\mathrm{0,}2)$

If , i = 1, 2, 3 are polynomials in x such that  and

F(x) =  
then (x) at x = a is equal to

a) – 1

b) 0

c) 1

d) 2

If  then f (x) increases in

a) (−2, 2)

b) No value of x

c) (0, ∞)

d) (−∞, 0)

A curve passes through the point $\left(\mathrm{1,}\frac{\pi }{6}\right)$

. Let the slope of the curve at each point (x, y) is $\frac{y}{x}+\sec \left(\frac{y}{x}\right)$ , x > 0. Then the equation of the curve is

a) $\sin \left(\frac{y}{x}\right)=\mathrm{lnx}+\frac{1}{2}$

b) $\mathrm{cosec}\left(\frac{y}{x}\right)=lnx+2$

c) $\sec \left(\frac{2y}{x}\right)=\mathrm{tanx}+2$

d) $\cos \frac{2y}{x}=lnx+\frac{1}{2}$

The points  in the complex plane are the vertices of a parallelogram if and only if

a)

b)

c)

d) None of these

Let f:[0, 1] → ℝ (the set all real numbers)be a function. Suppose the function is twice differentiable, f(0) = f(1) = 0 and satisfiesf′′(x) – 2f′(x) + f(x) ≥ e^x, x ∈ [0, 1]Which of the following is true?

a) $f\left(x\right)<\infty$

b) $\frac{-1}{2}<f\left(x\right)<\frac{1}{2}$

c) $\frac{-1}{4}<f\left(x\right)<1$

d) $-\infty <f\left(x\right)<0$

If ω(≠1) is a cube root of unity and  then A and B are respectively

a) 0, 1

b) 1, 1

c) 1, 0

d) – 1, 1

If (1 + x)ⁿ = C₀ + C₁x + C₂x² + .  .  . + C_nxⁿ, then show that the sum of the products of the C_j’s is taken two at a time represented by
 is equal to

Let a, b, c and d be non-zero real numbers. If the point of intersection of lines 4ax + 2ay + c = 0 and 5bx + 2by + d = 0 lie in the fourth quadrants and is equidistant from the two axes, then

a) 2bc – 3ad = 0

b) 2bc + 3ad = 0

c) 2ad – 3bc = 0

d) 3bc + 2ad = 0

One or more than one correct option

Let α, λ, μ ∈ ℝ. Consider the system of linear equations αx + 2y = λ 3x – 2y = μWhich of the following statements is/are correct?

a) If α = −3, then the system has infinitely many solutions for all values of λ and μ

b) If α ≠ −3, then the system of equations has a unique solution for all values of λ and μ

c) If λ + μ = 0, then the system has infinitely many solutions for α = −3

d) If λ + μ ≠ 0, then the system has no solution for α = −3

Let  and f = R – [R] where [ ] denotes the greatest integer function. Prove that Rf = 4^{2n + 4}

One or more than one correct option

Circle(s) touching X – axis at a distance 3 from the origin and having an intercept of length $2\sqrt{7}$

on Y – axis is/are

a) x² + y² – 6x + 8y + 9 = 0

b) x² + y² – 6x + 7y + 9 = 0

c) x² + y² – 6x − 8y + 9 = 0

d) x² + y² – 6x − 7y + 9 = 0

Using induction or otherwise, prove that for any non-negative integers m, n, r and k
 

Let V be the volume of the parallelepiped formed by the vectors  and . If a_r, b_r, c_r where r = 1, 2, 3 are non-negative real numbers and , show that V ≤ L³

One or more than one correct option

A circle S passes through the point (0, 1) and is orthogonal to the circles (x – 1)² + y² = 16 and x² + y² = 1, then

a) Radius of S is 8

b) Radius of S is 7

c) Centre of S is (−7, 1)

d) Centre of S is (−8, 1)

The locus of the midpoint of a chord of the circle  which subtend a right angle at the origin is

a)

b)

c)

d)

If n is a positive integer and 0 ≤ v < π then show that

A tangent PT is drawn to the circle x² + y² = 4 at the point $P\left(\sqrt{3},1\right)$

. A straight line L, perpendicular to PT is tangent to the circle (x – 3)² + y² = 1A possible equation of L is

a) $x-\sqrt{3}y=1$

b) $x+\sqrt{3}y=1$

c) $x-\sqrt{3}y=-1$

d) $x+\sqrt{3}y=5$

Let 0 < A_i < π for i = 1, 2, .  .  . n. Use mathematical induction to prove that
 
where n ≥ 1 is a natural number.

The centre of those circles which touch the circle x² + y² – 8x – 8y = 0, externally and also touch the X- axis, lie on

a) A circle

b) An ellipse which is not a circle

c) A hyperbola

d) A parabola