Recent questions and answers in Math

The potential difference across the collector of a transistor, used in common emitter mode is $1.5\;V,$ with the collector resistance of $3\;k \Omega.$ Find 1. The emitter and 2. The base current, if the d.c. gain of the transistor is $50$

answered Dec 12 by mg.sankkar

1 answer

Two bags A and B contain 2 white, 4 red and 3 white, 3 red balls respectively. One of the bags is selected at random and a ball is drawn from it. If the selected ball is of white colour, find the probability that it is drawn from bag A.

answered Dec 6 by hrithwikp

1 answer

Verify Lagrange's mean value theorem for the following function : $ f(x) = \sin \: x - \sin\: 2x \: in \: [0, \pi ] $

answered Dec 6 by kp5018800

1 answer

A catering agency has two kitchen to prepare food at two places A and B. From these places 'Mid-day Meal' is to be supplied to three different schools situated at P, Q , R. The monthly requirement of the school are respectively 40,40 and 70 food packets. A packet contains lunch for 1000 students. The capacity of kitchen A and B are 60 and 70 packets per month respectively. The transportation cost per packets from the kitchens to school is given below : How many packets from each kitchen should be transported to school so that the cost of transportation is minimum? Also find the minimum cost.

answered Nov 30 by vanshgreat08

1 answer

Find the scalar and vector components of the vector with initial point ( 2, 1 ) and terminal point ( -5, 7 ).

answered Nov 29 by ranjani.hogwarts

1 answer

tan^-1 + cos^-1(-1/2) + sin^-1(-1/2)

answered Nov 24 by gujjarkavitakasana

1 answer

Show that the four points ( 0, -1, -1 ), ( 4, 5, 1 ) and (-4, 4, 4 ) are coplanar. Also find the equation of the plane containing them.

answered Nov 21 by lneha286

1 answer

Examine which of the following is a binary operation.

answered Nov 21 by basumbonika96

1 answer

State the relation between the frequency $\gamma$ of radiation emitted by LED and the band gap energy $E$ of the semiconductor used to fabricate it .

answered Nov 20 by sukhnoorsingh234

1 answer

Find the equation of plane determined by the points A(3, -1, 2), B(5, 2, 4) and C(-1, -1, 6). Also find the distance of the point P(6, 5, 9) from the plane.

answered Nov 17 by adithya.vinod

1 answer

Find the foot of the perpendicular drawn from the point A(1,0,3) to the join of the points B(4,7,1) and C(3,5,3)

answered Nov 10 by gargtanu21

1 answer

Coloured balls are distributed in three bags as shown in the table below, a bag is selected at random and then two balls are randomly drawn from the selected bag. They happen to be black and red. what is the probability that they came from bag 1 ?

answered Nov 7 by classicshameer10

1 answer

Two dice are thrown. Find the probability that the number appeared have a sum 8 if it is known that second dice always exhibits 4.

answered Nov 2 by sk334122

1 answer

Prove that an angle in a semi-circle is a right angle (using vector only).

answered Oct 30 by ranjani.hogwarts

1 answer

Solve the differential equation $ (x+y)dy+(x-y)dx=0$

answered Oct 25 by avinashanand2017

1 answer

Solve the differential equation: dy/dx=(x+y+1)/(x+y)

answered Oct 21 by niteshp282000

1 answer

What is the polarizing angle of medium of refractive index $1.732$?

answered Oct 12 by lujianathary

1 answer

The surface area of a balloon being inflated, changes at a rate proportional to time t. If initially its radius is 1 unit and after 3 seconds it is 2 units, find the radius after time 't'.

answered Oct 7 by goyalpriyanka4567

1 answer

Show that the height of the cylinder of maximum volume that can be inscribed in a sphere of radius R is $ \frac{2R}{\sqrt 3} $. Find the volume of the largest cylinder inscribed in a sphere of radius R.

answered Sep 28 by ramssunny77

1 answer

The force on an electron kept in an electric field in a particular direction is F. What will be the magnitude and direction of the force experienced by a proton kept at the same point in the filed ? Mass of the proton is about $1836$ times the mass of the electron

answered Sep 2 by aditya.p2410

2 answers

Evaluate : $ \int \tan^{-1} \sqrt{ \large\frac{1-sinx}{1+sinx}}dx. $

answered Aug 9 by bhaskar.kumar582000

1 answer

A metallic sphere is placed in a uniform electric field as shown in the figure. which path is folllowed by electric field lines? why ?

answered Aug 9 by saniasalam2017

2 answers

Evaluate : $\tan^{-1} (1) + cos^{-1} ( \frac{-1}{2} )+ \sin^{-1} (\frac{-1}{2})$

answered Jul 16 by punitakharb430

2 answers

Let A = N x N and * be a binary operation on A defined by (a,b)(c,d)=(ac,bd), show that : (i) (A) is commutative. (ii) (A*) is associative (iii) Find the identity element, if any, in A.

answered Jul 8 by s.kpandey26

1 answer

If $ A=\begin{bmatrix} 3 & 1 \\ 7 & 5 \end{bmatrix}$ find x and y such that $ A^2+xl=yA.\;Find\;A^{-1}.$

answered Jun 20 by vasuloki708

1 answer

Show that of all the rectangles of given area, the square has the smallest perimeter.

answered Jun 9 by anshikamaheshwari28

1 answer

For what value of k is the following function continuous at x = 2? $ f(x) = \left\{ \begin{array}{l l} 2x+1, & \quad { x < 2}\\ k, & \quad \text{ $x$ = 2} \\ 3x-1, & \quad \text{ $x$ > 2} \end{array}. \right.$

answered May 29 by dwivediprachi09

1 answer

Give an example of relation which is reflexive but neither symmetric nor transitive.

answered Apr 11 by harishahmad6

1 answer

A square piece of tin of side 24 cm is to be made into a box without top by cutting a square from each corner and folding up the flaps to form a box. What should be the side of the square to be cut off so that volume of the box is maximum?

answered Apr 9 by rahulrkchauhan123456789

1 answer

A coin is based so that the head is 3 times as likely to occur as tail. If the coin is tossed three times, find the probabilty distribution of number of tails.

answered Mar 20 by akkhola2000

1 answer

A catering agency has two kitchens to prepare food at two places A and B. From these place " Mid-day meal' is to be supplied to three different schools situated at P, Q, R. The monthly requirements of the schools are respectively 40, 40 and 50 food packets. A packet contains lunch for 1000 students. Preparing capacity of kitchen A and B are 60 and 70 packets per month respectively. The transportation cost per packet for the kitchen to school is given below. How many packets from each kitchen should be transported to school so that the cost of transportation is minimum? Also find the minimum cost.

answered Mar 20 by prakashkumarsingh.ktr

1 answer

The function $ f(x)=2 log (x-2) - x^2+4x+1 $increases in the interval.\[(a)\;(1,2)\qquad(b)\;(2,3)\qquad(c)\;(5/2,3)\qquad(d)\;(2,4)\]

answered Mar 7 by ranjani.hogwarts

1 answer

The mean and variance of a binomial distribution are $ 4 \;and\;\frac{4}{3}.\;Find\;P(X\geq1).$

answered Feb 26 by Sumitchn007

1 answer

An open box is to be constructed by removing equal squares from each corner of a 3 metre by 8 metre rectangular sheet of aluminium and folding up the sides. Find the volume of the largest such box.

answered Feb 23 by pady_1

1 answer

The plane ax+by=0 is rotated about its line of intersection with the plane z=0 through an angle $\alpha$.Prove that the equation of the plane in its new position is $ax+by\pm \bigg(\sqrt {a^2+b^2}\tan \alpha\bigg)z=0$.

answered Feb 4 by sanjamdeep30

1 answer

A metal has a threshold wavelength of $6000 ^{\circ} A$. Calculate its 1) threshold frequency and 2) work function of the metal in eV.

answered Jan 31 by arunamansingh5

1 answer

In a game, a man wins a rupee for a six and loses a rupee for any other number when a fair die is thrown. The man decided to throw a die thrice but to quit as and when he gets a six. Find the expected value of the amount he wins / loses.

answered Jan 28 by sristijain30

2 answers

Solve the following differential equation : $ \cos^2\: x\large\frac{dy}{dx}$$+y=\tan x$

answered Jan 27 by chodadeepak14

1 answer

Prove that relation R defined on the set N of natural numbers by \[x\;R\;y \Leftrightarrow 2x^2-3xy+y^2=0\] is not symmetric but it is reflexive.

answered Jan 24 by nimmisivapuri.d5

1 answer

Let $f : A \rightarrow B$ be a given function. A relation R in the set A is given by $R = {(a,b) \varepsilon A \times A : f(a) = f(b)}.$ Check, if R is an equivalence relation.

answered Jan 24 by nimmisivapuri.d5

1 answer

Find the values of P so that the lines $ \Large\frac{1-x}{3}=\frac{7y-14}{2p}=\frac{z-3}{2}$ and $ \Large\frac{7-7x}{3p}=\frac{y-5}{1}=\frac{6-z}{5}$ are at right angles.

answered Jan 23 by adarsh06032000

1 answer

find the equation of the normal to the curve y=x^3+2x^2 at x=0 find the coo

asked Jan 18 by samwarke2000

0 answers

Two cards are drawn one by one without replacement from well shuffled pack of 52 cards. Find the probability distribution of the number of aces.

answered Jan 17 by mahawarravi036

2 answers

Probabilities of solving a specific problem independently by A and B are $ \frac{1}{2} \: and \frac{1}{3} $ respectively. If both try to solve the problem independently, find the probability that (i) the problem is solved (ii) exactly one of them solves the problem.

answered Jan 14 by next2unonu

1 answer

There are two bags I and II. Bag I contains 2 white and 3 red balls and Bag II contains 4 white and 5 red balls. One ball is drawn at random from one of the bags and is found to be red. Find the probability that it was drawn from bag II.

answered Jan 3 by zawude.tame

1 answer

True or False: If the determinant $\small\begin{vmatrix}x+a & p+u & l+ f\\y+b & q+v & m +g\\z+c & r+w & n + h\end{vmatrix}$ splits into exactly $k$ determinants of order $3$, each element of which contains online term,then the value of $k$ is $8$.

answered Dec 6, 2017 by priyanka.c

1 answer

Find the scalar components and magnitude of the vector joining the points $P (x_1, y_1, z_1)$ and $Q (x_2, y_2, z_2)$.

answered Dec 6, 2017 by priyanka.c

1 answer

Reshma wishes to mix two types of food P and Q in such a way that the vitamin contents of the mixture contains atleast 8 units of vitamin A and 11 units of vitamin B. Food P costs Rs. 60/kg and food Q costs Rs. 80/kg. Food P contains 3 units/kg of vitamin A and 5 units of vitamin B, while food Q contains 4 units/kg of vitamin A and 2 units/kg of vitamin B. Determine the minimum cost of the mixture.

answered Dec 2, 2017 by taha.ba16

1 answer

Evaluate : $ \begin{bmatrix} a+ib & c+id \\ -c+id & a-ib \end{bmatrix} $

answered Nov 22, 2017 by rabindrasinghrouth

1 answer

Give an account of Hershey and Chase experiment. What did it conclusively prove? If both DNA and pro

asked Jul 5, 2017 by pady_1

1 answer

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