हिंदी

If y=log[x+x2+a2] show that (x2+a2)d2ydx2+xdydx=0

Advertisements
Advertisements

प्रश्न

 

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

 
योग
Advertisements

उत्तर

 

It is given that:

`y=log[x+sqrt(x^2+a^2)]`

Differentiating equation (1) with respect to x, we get

`dy/dx=(1+x/sqrt(x^2+a^2))/(x+sqrt(x^2+a^2))`

`dy/dx=1/sqrt(x^2+a^2)........(2)`

`xdy/dx=x/sqrt(x^2+a^2).........(3)`

Again differentiating equation (2) with respect to x, we get

`(d^2y)/(dx^2)=-x/(x^2+a^2)^(3/2)`

`(x^2+y^2)(d^2y)/(dx^2)=-x/sqrt(x^2+a^2)............(4)`

Adding equation (3) and (4), we get

`(x^2+y^2)(d^2y)/(dx^2)+xdy/dx=-x/sqrt(x^2+a^2)+x/sqrt(x^2+a^2)=0`

`(x^2+y^2)(d^2y)/(dx^2)+xdy/dx=0`

 
shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
2012-2013 (March) Delhi Set 1

वीडियो ट्यूटोरियलVIEW ALL [3]

संबंधित प्रश्न

Differentiate the function with respect to x.

xx − 2sin x


Differentiate the function with respect to x.

`x^(xcosx) + (x^2 + 1)/(x^2 -1)`


Differentiate (x2 – 5x + 8) (x3 + 7x + 9) in three ways mentioned below:

  1. By using the product rule.
  2. By expanding the product to obtain a single polynomial.
  3. By logarithmic differentiation.

Do they all give the same answer?


If y = `e^(acos^(-1)x)`, −1 ≤ x ≤ 1, show that `(1- x^2) (d^2y)/(dx^2) -x dy/dx - a^2y = 0`.


if `x^m y^n = (x + y)^(m + n)`, prove that `(d^2y)/(dx^2)= 0`


Find `dy/dx` if y = xx + 5x


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


If `"x"^(5/3) . "y"^(2/3) = ("x + y")^(7/3)` , the show that `"dy"/"dx" = "y"/"x"`


 Solve the following differential equation: (3xy + y2) dx + (x2 + xy) dy = 0 


If y = (log x)x + xlog x, find `"dy"/"dx".`


If `log_10((x^3 - y^3)/(x^3 + y^3))` = 2, show that `dy/dx = -(99x^2)/(101y^2)`.


If x = `asqrt(secθ - tanθ), y = asqrt(secθ + tanθ), "then show that" "dy"/"dx" = -y/x`.


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


If log5 `((x^4 + "y"^4)/(x^4 - "y"^4))` = 2, show that `("dy")/("d"x) = (12x^3)/(13"y"^2)`


If y = 5x. x5. xx. 55 , find `("d"y)/("d"x)`


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


lf y = `2^(x^(2^(x^(...∞))))`, then x(1 - y logx logy)`dy/dx` = ______  


If `("f"(x))/(log (sec x)) "dx"` = log(log sec x) + c, then f(x) = ______.


`lim_("x" -> -2) sqrt ("x"^2 + 5 - 3)/("x" + 2)` is equal to ____________.


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 ______.


For which type of function is logarithmic differentiation especially useful?


If \[y=[u(x)]^{v(x)}\], which expression gives \[\frac{dy}{dx}\] in logarithmic differentiation?


After taking logarithms in logarithmic differentiation, which rules are used to simplify products, quotients and powers before differentiation?


What condition must be ensured for an expression inside logarithm?


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×