The equation of the tangent to the curve xa + yb&n

Subject

Mathematics

Class

JEE Class 12

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

11.

If ab > - 1, bc > - 1 and ca > - 1, then  is

  • - 1

  • cot-1abc

  • 0


12.

If the function fx = x2 - k + 2x +2kx - 2 for x  22                               for x = 2 is continuous at x = 2, then k is equal to

  • - 12

  • - 1

  • 0

  • 12


13.

If xexy + ye- xysin2x, then dydx at x = 0 is

  • 2y2 - 1

  • 2y

  • y2 - y

  • y2 - 1


14.

If y = tan-12x - 11 + x - x2, then dydx at x = 1 is equal to

  • 12

  • 23

  • 1

  • 32


Advertisement
15.

If f(x) = cos-12cosx + 3sinx13, then [f'(x)]2 is equal to

  • 1 + x

  • 1 + 2x

  • 2

  • 1


16.

If u = tan-11 - x2 - 1x and v = sin-1x, then dudv is equal to

  • 1 - x2

  • - 12

  • 1

  • - x


17.

If y = 11 + x + x2, then dydx is equal to

  • y2(2 + 2x)

  • - 1 + 2xy2

  • 1 + 2xy2

  • - y2(1 + 2x)


18.

If g(x) is the inverse of f(x) and f'(x) = 11 + x3, then g'(x) is equal to

  • g(x)

  • 1 + g(x)

  • 1 + {g(x)}3

  • 11 + gx3


Advertisement
Advertisement

19.

The equation of the tangent to the curve xa + yb = 1 at the point (x1, y1) is xax1 + yby1 = k. Then, the value of k is

  • 2

  • 1

  • 3

  • 3


B.

1

Given curve is,

xa + yb = 1       ...iOn differentiating w.r.t. to x, we get1a . 12x + 1b . 12ydydx = 0 dydx = - byax  dydxx1, y1 = - by1ax1 Equation of tangent passing through the point (x1, y1) isy - y1 = - by1ax1x - x1     yby1 - y1by1 = - xax1 + x1ax1 xax1 + yby1 = x1ax1 + y1by1 = x1a + y1b xax1 + yby1 = 1  from Eq. (i)         at x1, y1, x1a + y1b = 1But, xax1 + yby1 = k                            k = 1


Advertisement
20.

The slope of the normal to the curve x = t2 + 3t - 8 and y = 2t2 - 2t - 5 at the point (2, - 1) is

  • 67

  • - 67

  • 76

  • 76


Advertisement