The value of dydx at x = π2, whe

Previous Year Papers

Download Solved Question Papers Free for Offline Practice and view Solutions Online.

Test Series

Take Zigya Full and Sectional Test Series. Time it out for real assessment and get your results instantly.

Test Yourself

Practice and master your preparation for a specific topic or chapter. Check you scores at the end of the test.
Advertisement

 Multiple Choice QuestionsMultiple Choice Questions

391.

The degree of the differential equation x = 1 + dydx + 12!dydx2 + 13!dydx3 + ...

  • 3

  • 2

  • 1

  • not defined


392.

Solution of the differential equation xdy - ydx = 0 represents a

  • parabola

  • circle

  • hyperbola

  • straight line


393.

The general solution of the differential equation

dydx = ey + x + ey - x is

  • e- y = ex - e- x + c

  • e- y = e- x - ex + c

  • e- y = ex + ex + c

  • ey = ex + e- x + c


394.

The order of the differential equation

d2ydx2 = 1 + dydx2 is

  • 3

  • 2

  • 1

  • 4


Advertisement
395.

The degree of the differential equation

1 + dydx253 = d2ydx2 is

  • 1

  • 5

  • 103

  • 3


396.

The differential equation of all parabolas whose axes are parallel to y-axis, is

  • d3ydx3 = 0

  • d2ydx2 = 0

  • d2ydx2 + dydx = 0

  • d2ydx2 + dydx + y = 0


397.

The solution of the differential equation dydx = ey + x + ey - x is

  • e- y = ex - e- x + c, c integrating constant

  • e- y = e- x - ex + c, c integrating constant

  • e- y = ex + e- x + c, c integrating constant

  • e- y + ex - e- x = c, c integrating constant


398.

If x = etsint, y = etcost, then d2ydx2 at x = π is

  • 2eπ

  • 12eπ

  • 12eπ

  • 2eπ


Advertisement
Advertisement

399.

The value of dydx at x = π2, where y is given by y = xsinx + x, is

  • 1 + 12π

  • 1

  • 12π

  • 1 - 12π


A.

1 + 12π

Since, y = xsinx + xLet, y1 = xsinx and y2 = xTaking log on both sides, we getlogy1 = sinxlogxOn differentiating w.r.t. x, we get       1y1 . dy1dx = cosxlogx + 1xsinx           dy1dx = xsinxcosxlogx + 1xsinx dydxx = π2 = π2sinπ2cosπ2logπ2 + 2πsinπ2                        = π2 × 2π = 1

Now, y2 = xOn differentiating w.r.t. x, we getdy2dx = 12x dy2dxx = π2 = 12π2 = 12πSince, y = y1 + y2 dydx = dy1dx + dy2dx            = 1 + 12π


Advertisement
400.

The order and degree of the following differential equation 1 + dydx252 = d3ydx3 are respectively

  • 3, 2

  • 3, 10

  • 2, 3

  • 3, 5


Advertisement