Recent questions and answers in Math

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1 answer

During reproduction, the chromosome number (2n) reduces to half (n) in the gametes and again the ori

answered Jun 14 by pady_1

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2 answers

Form the differential equation of the family of circles having centre on $y$-axis and radius $3$ units.

answered Jun 5 by rslv8331

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The total revenue received from the sale of x units of a product is given by $ R(x) = 13x^2 + 26x + 15 $ Find the marginal revenue when x = 7.

answered Jun 3 by ranjani.hogwarts

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Find the area included between the parabolas $ y^2=4ax\;and\;x^2=4ay$

answered May 24 by sai.manohar044

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Find the equation of the plane passing through the point (1,6,3) and perpendicular to the plane 2x+3y-z = 7

answered May 22 by vikkyravi0106

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1 answer

find intervals in which function given by f(x) = sin 3x where x belongs [0, pi/2] is 1 increasing 2 decreasing

answered May 13 by nikunjjain285

+1 vote

1 answer

The ground state energy of hydrogen atom is $-13.6\;eV$ 1.What are the potential and kinetic energy of an electron in the 3rd excited state? 2.If the electron jumps to the ground state from the third excited state, calculate the frequency of the photon emitted.

answered May 11 by balaramshil1

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1 answer

A company has two plants to manufacture bicycles. Plant I manufactures 70% of the bicycles and plant II manufactures 30%. At plant I 80% of the bicycles are rated as of standard quality and a plant II 90% of the bicycles are rated as of standard quality. A bicycle is choosen at random and is found to be of standard quality. What is the probability that it has come from plant II?

answered Apr 14 by shrutibhagat2215

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1 answer

A company sells two different products A and B. The products are produced in a common production process which has total capacity of 500 man hours. It takes 5 hours to produce a unit of A and 3 hours to produce a unit of B. The demand in the market shows that the maximum number of units of A that can sold is 70 and that of B is 125. Profit on each unit of A is Rs. 20 and on B is Rs.15. How many units of A and B should be produced to maximise the profit? Form an L.P.P and solve it graphically.

answered Feb 16 by meena.p

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1 answer

If $ \overrightarrow a \: and \: \overrightarrow b$ are two vectors such that $ | \overrightarrow a. \overrightarrow b| = | \overrightarrow a$ x $ \overrightarrow b |$, then what is the angle between $ \overrightarrow a \: and \: \overrightarrow b$?

answered Feb 16 by suganyadevi.p

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1 answer

Using properties of determinants, solve the following for x : $\begin{vmatrix} x+a & x & x \\ x & x+a & x \\ x & x & x+a \end{vmatrix} = 0 $

answered Feb 16 by meena.p

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1 answer

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

answered Feb 16 by suganyadevi.p

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1 answer

A card from a pack of 52 playing cards is lost. Two cards are drawn from the remaining cards and found to be both spade. (i) Find the probability of lost card being a spade card.(ii)While playing in ground you found a purse containing rupees and some other documents,what will you do?

answered Feb 16 by meena.p

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1 answer

If vectros $ \overrightarrow a = 2\hat i + 2\hat j +3\hat k , \overrightarrow b = -\hat i + 2\hat j +\hat k \: and \: \overrightarrow c = 3\hat i + \hat j $ are such that $ \overrightarrow a +\lambda \overrightarrow b$ is perpendicular to $ \overrightarrow c $, then find the value of $ \lambda $

answered Feb 16 by suganyadevi.p

0 votes

1 answer

If $x=a(\theta - \sin \theta) \quad ; y= a(1+\cos \theta) $ find $\large\frac{d^2y}{dx^2}$ at $\theta =\large\frac{\pi}{2}$

answered Feb 16 by meena.p

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1 answer

The scalar product of the vector $ \overrightarrow a = \hat i + \hat j + \hat k$ with a unit vector along the sums of vectors $ \overrightarrow b = 2 \hat i + 4\hat j - 5 \hat k$ and $ \overrightarrow c = \lambda \hat i + 2 \hat j + 3 \hat k$ is equal to one. Find the value of $ \lambda $ and hence find the unit vector along $ \overrightarrow b + \overrightarrow c$

answered Feb 16 by meena.p

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1 answer

Evaluate : \[ \int_{-a}^a \sqrt{\frac{a-x}{a+x}}dx \]

answered Feb 16 by meena.p

–1 vote

1 answer

If $x^{my^n}=(x+y)^{m+n}$, prove that $\large\frac{dy}{dx}=\frac{y}{x}$

answered Feb 15 by meena.p

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1 answer

If $A$ is a square matrix such that $A^2=A$, then write the value of $7A -(I+A)^3$ where $I$ is an identity matrix.

answered Feb 15 by meena.p

0 votes

1 answer

A wire of length 36 cm is cut into two pieces. One of the pieces is turned in the form of a square and the other in the form of an equilateral triangle. Find the length of each piece so that the sum of the areas of the two be minimum.

answered Feb 15 by meena.p

0 votes

1 answer

In a hurdle race, a player has to cross 10 hurdles. The probability that he will clear each hurdle is $ \frac{5}{6} $, What is the probability that he will knock down fewer than 2 hurdles.

answered Feb 15 by meena.p

0 votes

1 answer

Assume that the chances of a patient having a heart attack is 40%. It is assumed that a meditation and yoga course reduce the risk of heart attack by 30% and prescription of certain drug reduces its chance by 25%. At a time, a patient can choose any one of the two options with equal probabilities. It is given that after going through one of the two options the patient selected at random suffers a heart attack. Find the probability that the patient followed a course of meditation and yoga?

answered Feb 15 by meena.p

0 votes

1 answer

If a point charge be rotated in an arc of radius r around a change q, what will be the workdone ? explain

answered Feb 15 by meena.p

0 votes

1 answer

Show that the volume of the greatest cylinder which can be inscribed in a cone of height h and semivertical angle $ \alpha, \: is \: \large\frac{4}{27}$$ \pi \: h^3\: tan^2\: \alpha $

answered Feb 15 by asewa44

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1 answer

A variable plane is at constant distance p from the origin and meet the axes in A, B & C. Show that the locus of the centroid of the tetrahedron $\bigtriangleup ABC\;is\; \Large\frac{1}{x^2}+\frac{1}{y^2}+\frac{1}{z^2}=\frac{16}{p^2}$

answered Feb 4 by loserlady2lol

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1 answer

A variable plane which remains at a constant distance 3p from the origin cuts the co-ordinate axes at A, B & C. Show that the locus of the centroid of the $ \bigtriangleup ABC\;is\; \Large\frac{1}{x^2}+\frac{1}{y^2}+\frac{1}{z^2}=\frac{1}{p^2}$

answered Feb 4 by loserlady2lol

0 votes

0 answers

Which one of the following is a bird flu virus?

asked Jan 25 by priyanka.c

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1 answer

A firm makes two types of furniture : chairs and tables. The contribution to profit for each product as calculated by the accounting department is Rs.20 per chair and Rs.30 per table. Both products are to be processed on three machines $ M_1,M_2 and M_3.$ The time required in hours by each product and total time available in hours per week on each machine are as follows:

answered Jan 9 by stefanosstvm

0 votes

1 answer

If the points $(1,1,p)$ and $(-3,0,1)$ are at equidistant from the plane $\overrightarrow {r} . (3 \hat {i} +4 \hat {j} -12 \hat {k}) + 13 = 0, $ then find the value of p.

answered Dec 28, 2016 by priyanka.c

0 votes

1 answer

Form the differential equation of the family of circles in the first quadrant which touch the coordinate axes.

answered Dec 27, 2016 by priyanka.c

0 votes

1 answer

An oil company has two depots A and B with capacities of 7000 L and 4000 L respectively. The company is to supply oil to three petrol pumps, D, E and F whose requirements are 4500L, 3000L and 3500L respectively. Assuming that the transportation cost of 10 litres of oil is Rs 1 per km, How should the delivery be scheduled in order that the transportation cost is minimum ? What is the minimum cost? The distance (In km) between the depots and the petrol pumps is given in the following table :

answered Dec 27, 2016 by priyanka.c

0 votes

1 answer

Suppose a girl throws a die. If she throws a 5 or 6, she tosses a coin 3 times and notes the number of heads. If she gets 1, 2, 3 or 4, she tosses a coin once and notes whether a head or tail is obtained. If she obtained exactly one head, what is the probability that she threw 1, 2, 3 or 4 with a die?

answered Dec 27, 2016 by priyanka.c

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1 answer

Find the area of the region $\{ (x,y) : 0 \leq y \leq x^2, 0 \leq y \leq x+2 , 0 \leq x \leq 3\}$

answered Dec 27, 2016 by priyanka.c

0 votes

1 answer

Find the image of the point (1, 3. 4) in the plane $x-y+z =5$. Hence show that the image lies on the plane $x -2y +z -7 = 0$

answered Dec 27, 2016 by priyanka.c

0 votes

1 answer

Radioactive wastes is to be disposed of in full enclosed lead boxes of inner volume $200 cm^3$. The base of the box has dimension in the ratio 2:1 . What is the inner length of the box. Find the minimum inner surface area of the box.

answered Dec 22, 2016 by priyanka.c

0 votes

1 answer

Rent -a-car has three different makes of vehicles P, Q and R for hire. These cars are located at stations A and B on either side of a city. Some cars are being rented. In total they have 150 cars. At station A, they have 20% of P, 40% of Q and 30% of R which is 46 cars in total. At station B they have 40% of P, 20% of Q and 50% of R which is 54 cars in total. How many of each cars types does Rent-a -car have ?

answered Dec 22, 2016 by priyanka.c

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1 answer

Integrate $\begin{align} \int \frac{\sin(x+a)}{\sin (x+b)} dx\end{align} $

answered Dec 22, 2016 by priyanka.c

0 votes

1 answer

Express the matrix $A = \begin{bmatrix} 3 & 2 & 3 \\ 4 & 5 & 3 \\ 2 & 4 & 5 \end{bmatrix}$ as the sum of a symmetric and a skew symmetric matrix.

answered Dec 22, 2016 by priyanka.c

0 votes

1 answer

Assume that each child born is equally likely to be a boy or a girl. If a family has two children, what is the conditional probability that both are girls given that
(a) The youngest is a girl.
(b) At least one is a girl.
Pre-natal * determination is a crime. What will you do if you come to know that some of your known is indulging in pre-natal * determination ?

answered Dec 22, 2016 by priyanka.c

0 votes

1 answer

Evaluate $\begin{align} \int_{-1}^{3/2} |x \sin {\pi \; x}| dx \end{align}$

answered Dec 22, 2016 by priyanka.c

0 votes

1 answer