हिंदी

If y = log (log 2x), show that xy2 + y1 (1 + xy1) = 0. - Mathematics and Statistics

Advertisements
Advertisements

प्रश्न

If y = log (log 2x), show that xy2 + y1 (1 + xy1) = 0.

योग

उत्तर

y = log (log 2x)

∴ `"dy"/"dx" = "d"/"dx"[log(log2x)]`

= `(1)/"log2x"."d"/"dx"(log2x)`

= `(1)/"log2x" xx (1)/(2x)."d"/"dx"(2x)`

= `(1)/"log2x" xx (1)/(2x) xx 2`

∴ `"dy"/"dx" = (1)/(xlog2x)`

∴ `(log2x)."dy"/"dx" = (1)/x`                 ...(1)
Differentiating both sides w.r.t. x, we get

`(log2x)."d"/"dx"(dx/dy) + "dy"/"dx"."d"/"dx"(log2x) = "d"/"dx"(1/x)`

∴ `(log2x).(d^2y)/(dx^2) + "dy"/"dx".(1)/(2x)."d"/"dx"(2x) = -(1)/x^2`

∴ `(log2x).(d^2y)/(dx^2) + "dy"/"dx".(1)/(2x) xx 2 = -(1)/x^2`

∴ `(log2x).(d^2y)/(dx^2) + (1)/x."dy"/"dx" = (1)/x.(1)/x`

∴ `(log2x).(d^2y)/(dx^2) + [(log2x)."dy"/"dx"]"dy"/"dx" = -(1)/x[(log2x)."dy"/"dx"]`     ...[By (1)]

Dividing throughout by log 2x, we get

`(d^2y)/(dx^2) + (dy/dx)^2 = -(1)/x"dy"/"dx"`

∴ `x(d^2y)/(dx^2) + x(dy/dx)^2 = -"dy"/"dx"`

∴ `x(d^2y)/(dx^2) + "dy"/"dx" + x(dy/dx)^2` = 0

∴ `x(d^2y)/(dx^2) + "dy"/"dx" (1 + xdy/dx)` = 0

∴ xy2 + y1 (1 + xy1) = 0.

shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 1: Differentiation - Exercise 1.5 [पृष्ठ ६०]

APPEARS IN

संबंधित प्रश्न

 

If `y=log[x+sqrt(x^2+a^2)] ` show that `(x^2+a^2)(d^2y)/(dx^2)+xdy/dx=0`

 

 

if xx+xy+yx=ab, then find `dy/dx`.


Differentiate the function with respect to x.

`(log x)^(cos x)`


Differentiate the function with respect to x.

(x + 3)2 . (x + 4)3 . (x + 5)4


Differentiate the function with respect to x.

`(x + 1/x)^x + x^((1+1/x))`


Differentiate the function with respect to x.

xsin x + (sin x)cos x


Differentiate the function with respect to x.

`(x cos x)^x + (x sin x)^(1/x)`


Find `dy/dx`for the function given in the question:

xy + yx = 1


Find `dy/dx` for the function given in the question:

yx = xy


Find `dy/dx` for the function given in the question:

(cos x)y = (cos y)x


Find the derivative of the function given by f (x) = (1 + x) (1 + x2) (1 + x4) (1 + x8) and hence find f ′(1).


Differentiate w.r.t. x the function:

xx + xa + ax + aa, for some fixed a > 0 and x > 0


Differentiate  
log (1 + x2) w.r.t. tan-1 (x)


xy = ex-y, then show that  `"dy"/"dx" = ("log  x")/("1 + log x")^2`


If `(sin "x")^"y" = "x" + "y", "find" (d"y")/(d"x")`


If xy = ex–y, then show that `"dy"/"dx" = logx/(1 + logx)^2`.


If x = a cos3t, y = a sin3t, show that `"dy"/"dx" = -(y/x)^(1/3)`.


If x = log(1 + t2), y = t – tan–1t,show that `"dy"/"dx" = sqrt(e^x - 1)/(2)`.


Differentiate 3x w.r.t. logx3.


Find the nth derivative of the following : log (2x + 3)


If y = `25^(log_5sin_x) + 16^(log_4cos_x)` then `("d"y)/("d"x)` = ______.


If x7 . y5 = (x + y)12, show that `("d"y)/("d"x) = y/x`


If y = `(sin x)^sin x` , then `"dy"/"dx"` = ?


The rate at which the metal cools in moving air is proportional to the difference of temperatures between the metal and air. If the air temperature is 290 K and the metal temperature drops from 370 K to 330 K in 1 O min, then the time required to drop the temperature upto 295 K.


`d/dx(x^{sinx})` = ______ 


If y = `("e"^"2x" sin x)/(x cos x), "then" "dy"/"dx" = ?`


`8^x/x^8`


`log (x + sqrt(x^2 + "a"))`


If y = `log ((1 - x^2)/(1 + x^2))`, then `"dy"/"dx"` is equal to ______.


If `"f" ("x") = sqrt (1 + "cos"^2 ("x"^2)), "then the value of f'" (sqrtpi/2)` is ____________.


If y = `(1 + 1/x)^x` then `(2sqrt(y_2(2) + 1/8))/((log  3/2 - 1/3))` is equal to ______.


Derivative of log (sec θ + tan θ) with respect to sec θ at θ = `π/4` is ______.


If y = `log(x + sqrt(x^2 + 4))`, show that `dy/dx = 1/sqrt(x^2 + 4)`


The derivative of log x with respect to `1/x` is ______.


If xy = yx, then find `dy/dx`


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×