InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 4601. |
Prove that (.^(n)C_(1)sin2x+.^(n)C_(2)sin4x+.^(n)C_(3)sin6x+"…..")/(1+.^(n)C_(1)cos2x+.^(n)C_(2)cos4x+.^(n)C_(3)cos 6x+"……") |
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Answer» SOLUTION :L.H.S. `=(underset(r=0)overset(n)SUM.^(n)C_(r)sin2rx)/(underset(r=0)overset(n)sum.^(n)C_(r)cos2x)""(1)` `0=(underset(r=0)overset(n)sum.^(n)C_(n-r)sin2(n-r)x)/(underset(r=0)overset(n)sum.^(n)C_(n-r)COS2(n-r)x)` `=(underset(r=0)overset(n)sum.^(n)C_(r)sin(2n-2r)x)/(underset(r=0)overset(n)sum.^(n)C_(r)cos(2n-2r)x)""(2)` `=(underset(r=0)overset(n)sum.^(n )C_(r)sin2rx+underset(r=0)overset(n)sum.^(n)C_(r)sin(2n-2r)x)/(underset(r=0)overset(n)sum.^(n)C_(r)cos2rx+underset(r=0)overset(n)sum.^(n)C_(r)cos(2n-2r)x)`. (USING `a/b = c/d = (a+c)/(b+d)` and using (1) and (2)) `=(underset(r=0)overset(n)sum.^(n)C_(r)[sin2rx+sin(2n-2r)x])/(underset(r=0)overset(n)sum.^(n)C_(r)[cos2rx+cos(2n-2r)x])` `= (2sin nx underset(r=0)overset(n)sum.^(n)C_(r)cos(2r-n)x)/(2cos nx underset(r=0)overset(n)sum.^(n)C_(r)cos(2r-n)x) = tan nx` |
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| 4602. |
a, b, c are digits of a 3-digit number such that 64a + 8b + c = 403, then the value of a + b + c + 2013 is |
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| 4603. |
Find the inverse of the following using elementary transformations. A=[[3,1],[5,2]] |
| Answer» SOLUTION :`A^(-1) = [(2,-1),(-5,3)]` | |
| 4604. |
Determine the truth of falsity of the"Every set has a proper subset" propositions with reasons. |
| Answer» SOLUTION :EVERY set. has a PROPER SUBSET is false as `PHI` has no proper subset. | |
| 4605. |
Evalute the following integrals int x^(3) e^(2x) dx |
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| 4606. |
Verify that the given function (explicit or implicit) isa solution of the correseponding differential equation :y = x^2 + 2x +c:y' - 2x - 2 = 0 |
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Answer» Solution :`y= x^2 + 2x + C` `rArr y. = 2x + 2` `rArr y. - 2x - 2 = 0` `THEREFORE y = x^2 + 2x + c` is a solution of y. - 2x -2= 0 |
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| 4607. |
Verify that the given function (explicit or implicit) isa solution of the correseponding differential equation : y = e^x + 1: y'' - y' = 0 |
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Answer» SOLUTION :` y = e^x + 1` `RARR y. = e^x` `rArr y.. = e^x = y.` `THEREFORE y.. - y. = 0 ` Therefore, `y = e^x + 1` is a solution of y.. - y. = 0 |
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| 4608. |
Verify that the given function (explicit or implicit) isa solution of the correseponding differential equation : y = sqrt(1 + x^2): y' = (xy)/(1 + x^2) |
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Answer» SOLUTION :`y = sqrt(1 + x^2)` `y.= 1/(2 sqrt(1+x^2)) (0+2x)` `=x/sqrt(1+x^2) = (xsqrt(1+x^2))/(1+x^2) = (xy)/(1 + x^2) ` `THEREFORE y = sqrt(1 + x^2)` is a solution of `y. = (xy)/(1+x^2)` |
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| 4609. |
Verify that the given function (explicit or implicit) isa solution of the correseponding differential equation : y = cos x + c: y' + sin x = 0 |
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Answer» SOLUTION :y = cos x + C y. = -SIN x `rArr y. + sin x = 0` ` THEREFORE` y = cos x + c is a solution of y. + sin x = 0 |
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| 4610. |
Derivative of e^(3 log x)w.r.t.x is 3x^2. |
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| 4612. |
The volume of a sphere is increasing at the rate of pi cm^(2)//sec. The rate at which the radius is increasing is ……….., when the radius is 3 cm. |
| Answer» Answer :A | |
| 4613. |
The normal at a point P to the parabola y^(2) = 4x is parallel to the tangent at Q sqrt(2,2) to the hyperbola nd meets the axis of the parabola at If 5 is the focus of the parabola, area of the triangle PSR in sq. units is |
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Answer» `9sqrt(2)` |
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| 4614. |
If A^T=[[-2,3],[1,2]] and B^T=[[-1,0],[1,2]] then find (A+2B)^T |
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Answer» SOLUTION :we have `(A+2B)^T=A^T+(2B)^T=A^T+2B^T` ` B^T=[[-1,0],[0,2]] IMPLIES 2B^T=[[-2,0],[0,4]]` THUS, `(A+2B)^T=A^T+2B^T=[[-4,5],[1,6]]` |
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| 4616. |
If a+b+c=0 and |a|=5, |b|=3 and |c|=7, then angle between a and b is |
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Answer» `pi/2` `impliesa+b=-c` On squaring both SIDES, we get `(a+b)^(2)=(-c)^(2)IMPLIES|a+b|^(2)=|c|^(2)` `implies|a|^(2)+|b|^(2)+2a*b=|c|^(2)` `[because theta` be the ANGLE between a and b] `implies(5)^(2)+(3)^(2)+2|a||b|cos theta =(7)^(2)` `implies25+9+2.5.3cos theta =49` `implies30 cos theta =15` `implies cos theta =1/2=cos 60^(@)` `impliestheta =(pi)/(3)` |
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| 4617. |
If n is an integer other than a multiple of 3, then the value of 1 + omega^(n) + omega^(2n) is |
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Answer» 1 |
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| 4618. |
If a times b=c" and "b times c=a, then |
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Answer» a, B, c are orthogonal in PAIRS but `ABS(a) ne abs(c)` |
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| 4620. |
Find the number of non negative integral solutions of x_(1)+x_(2)+x_(3)+x_(4)le20 |
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| 4622. |
The orthogonal trajectories of the family of curves a^(n-1)y=x^(n) are give by |
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Answer» `X^(n)+n^(2)y=` constant |
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| 4623. |
If x+iy=sqrt(phi+iy), where i=sqrt(-1)" and "phi and Psi are non-zero real parameters, then phi" and "Psi are constants, represents two system of rectangular hyperbola which intersect at an angle of : |
| Answer» Answer :D | |
| 4625. |
If A is a skew Hermitian matrix then the main diagonal elements of A are all |
| Answer» Answer :D | |
| 4626. |
If the second and fifth terms of a G.P. are 24 and 3 respectively, then the sum of first six terms is |
| Answer» ANSWER :D | |
| 4627. |
If the circles x^2+y^2-2lambda x-2y-7=0 and 3(x^2+y^2)-8x+29y=0 are orthogonal then lambda= |
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Answer» 4 |
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| 4628. |
Differentiate the following w.r.t.x 2sin^-1x+tan^-1x+1 |
| Answer» SOLUTION :`d/dx(2sin^-1x+tan^-1x+1)=2XX1/(SQRT(1-x^2))+1/(1+x^2)+0=2/(sqrt1-x^2)+1/(1+x^2)` | |
| 4629. |
If (1+x-2x^2)^8 = 1 + a_1x + a_2x^2 + ……+ a_16 x^16, then a_1 +a_3 + a_5 + ……+a_15 = |
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Answer» `2^7` |
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| 4630. |
If z_1 & z_2 are two complex number & if arg (z_1+z_2)/(z_1-z_2)=pi/2 but |z_1+z_2|ne|z_1-z_2| thenthe figure formed by the points represented by 0, z_1, z_2 & z_1 + z_2is |
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Answer» a parallelogram but not a rectangle or a RHOMBUS |
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| 4631. |
Find the equation of the circle whose diameter is the common chord of the circles x^2+y^2+2x+3y+1=0 and x^2+y^2+4x+3y+2=0 |
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| 4632. |
Evalute the following integrals int sqrt(1 + sec x )dx on ((2n - (1)/(2)) pi, (2n + (1)/(2)) pi, (n in z )) |
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| 4633. |
Area of the triangle with vertices (a, b ), (x_(1), y_(1)) and (x_(2), y_(2)), where a, x_(1), x_(2) are in G.P. with common ratio r and b, y_(1), y_(2) are in G.P. with common ratio s is : |
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Answer» `AB(r-1) (s-1) (s-r)` |
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| 4634. |
Let f (x,y) = (2xy)/(x ^(2)+2y ^(2)) (x,y) ne (0,0) =0 if (x,y) = (0,0) Show that f (x,y) is not continuous at (0,0) through continuous at all other points of R ^(2). |
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| 4635. |
Eleven apples are distributed between a girl and a boy.Then which one of the following statements is true? |
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Answer» ATLEAST one of them will receive 7 apples. |
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| 4636. |
Minimize and Maximize z=600x+400y Subject to the constraints : x+2y le 12 2x+y le 12 4x+5y ge 21 and xge0,y ge 0 graphical method. |
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| 4637. |
If a=sin(Cot^(-1)x)andb=cot(Sin^(-1)x) where xgt0, then 1//x^(2)-x^(2)= |
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Answer» `B^(2)/a^(2)` |
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| 4638. |
Evaluate the following definite integrals . int_(-1)^(1)e^(x)dx |
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| 4639. |
Lat l_(1)=int_(0)^(3)(sinx)/([(x)/(pi)]+(1)/(2))dx and l_(2)=int_(-3)^(0)(sinx)/([(x)/(pi)]+(1)/(2))dx, then (where[.] represent G.l.F.) |
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Answer» `l_(2)+l_(2)=0` and `l_(2) =underset(-3)overset(0)(int)(sinx)/([(x)/(pi)]+(1)/(2))dx=underset(-3)overset(0)(int)(sinx)/(-1+(1)/(2))dx=underset(-3)overset(0)(int)-2sinx dx = underset(0)overset(3)(int)2sin x dx""thereforel_(1)=l_(2)` |
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| 4640. |
If f is a continuous and differentiable funciton in x in (0, 1) such that Sigma_(r=0)^(10)(f(x+r)-|e^(x)-r-1|)=0, then int_(0)^(11)f(x)dx is |
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Answer» `65+4ln 2 -7E` |
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| 4641. |
If S-= x^(2) + y^(2) + 2gx + 2fy + c= 0repre- sents a circle then show that the straight line lx + my + n = 0 (i) touches the circle S = 0 if (g^(2)+f^(2)-c) = ((gl+mf-n)^(2))/((l^(2)+m^(2))) |
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| 4642. |
Delta=|{:(a_1,b_1,c_1),(a_2,b_2,c_2),(a_3,b_3,c_3):}|and Delta'|{:(A_1,B_1,C_1),(A_2,B_2,C_2),(A_3,B_3,C_3):}| where A_1,B_1,C_1,A_2,B_2,……… are respectively the cofactors of the elements a_1,b_1,c_1,a_2,b_2,….. of the determinant then Delta'=........ |
| Answer» ANSWER :C | |
| 4643. |
For eachof the following differential equations , determine its order , degree ( if exist ) ((d^(2)y)/(dx^(2))) + ((dy^(2))/(dx))^(2)= x sin ((d^(2)y)/(dx^(2))) |
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| 4644. |
int(dx)/((1+x)^(5)sqrt(x^2+2x))=(-1)/(8)(3theta-2sin2theta+(sin4theta)/(4))+C, where : |
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Answer» `theta=sin^(-1)(x+1)` |
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| 4645. |
Iftheta is the angle between the pair of linesax^(2)+2hxy+by^(2)=0 then prove thatcostheta=(a+b)/(sqrt((a-b))+4h^(2)) |
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| 4647. |
Integrate the following rational functions : int(5x)/((x+1)-(x^(2)+9))dx |
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| 4648. |
Solution the differential equation (dy)/(dx) + 1 = e^(x+y) is |
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Answer» `E^(-(x+y))+y = C` |
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| 4649. |
If1 , omega , omega^(2)are the cube roots of unity prove that x^(2) + 4x + 7 = 0 " where " x = omega - omega^(2) - 2. |
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| 4650. |
Let three matrices A = [(-1,3,2),(2,-1,3),(1,2,3)], B = , C = [(-2,2,-1),(3,-5,4),(5,-6,4)] The value of log_(sqrt(8/7))[Tr^(2)(A) + +Tr^(3) ((ABC)/(2))+ Tr^(3) ((A(BC)^(2))/(2))+Tr^(3) ((A(BC)^(2))/(2))+.....+ oo] is [Note : Tr. (P) denote trace of matrix P] and Tr^(3)(A) = (Tr(A))^(3) |
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Answer» `-4` `TR(A) = -1 - 1 + 3 = 1` `Tr((ABC)/2) = Tr(A/2) = 1/2` `Tr^(2)(A) + +Tr^(3) ((ABC)/(2))+ Tr^(3) ((A(BC)^(2))/(2))+Tr^(3) ((A(BC)^(2))/(2))+.....+ oo` `= 1^(3) + (1/2)^(3) + (1/4)^(3) + (1/8)^(3) + oo` `= 1/(1 - 1/8) = 1/(7/8) = 8/7`. |
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