English

2 X + 3 X − 2

Advertisements
Advertisements

Question

\[\sqrt{2 x^2 + 1}\]

Advertisements

Solution

\[ \frac{d}{dx}\left( f(x) \right) = \lim_{h \to 0} \frac{f\left( x + h \right) - f\left( x \right)}{h}\]
\[ = \lim_{h \to 0} \frac{\sqrt{2 \left( x + h \right)^2 + 1} - \sqrt{2 x^2 + 1}}{h}\]
\[ = \lim_{h \to 0} \frac{\sqrt{2 x^2 + 2 h^2 + 4xh + 1} - \sqrt{2 x^2 + 1}}{h}\]
\[ = \lim_{h \to 0} \frac{\sqrt{2 x^2 + 2 h^2 + 4xh + 1} - \sqrt{2 x^2 + 1}}{h} \times \frac{\sqrt{2 x^2 + 2 h^2 + 4xh + 1} + \sqrt{2 x^2 + 1}}{\sqrt{2 x^2 + 2 h^2 + 4xh + 1} + \sqrt{2 x^2 + 1}}\]
\[ = \lim_{h \to 0} \frac{2 x^2 + 2 h^2 + 4xh + 1 - 2 x^2 - 1}{h\left( \sqrt{2 x^2 + 2 h^2 + 4xh + 1} + \sqrt{2 x^2 + 1} \right)}\]
\[ = \lim_{h \to 0} \frac{h\left( 2h + 4x \right)}{h\left( \sqrt{2 x^2 + 2 h^2 + 4xh + 1} + \sqrt{2 x^2 + 1} \right)}\]
\[ = \lim_{h \to 0} \frac{\left( 2h + 4x \right)}{\left( \sqrt{2 x^2 + 2 h^2 + 4xh + 1} + \sqrt{2 x^2 + 1} \right)}\]
\[ = \frac{4x}{\sqrt{2 x^2 + 1} + \sqrt{2 x^2 + 1}}\]
\[ = \frac{4x}{2\sqrt{2 x^2 + 1}}\]
\[ = \frac{2x}{\sqrt{2 x^2 + 1}}\]

shaalaa.com
  Is there an error in this question or solution?
Chapter 30: Derivatives - Exercise 30.2 [Page 25]

APPEARS IN

R.D. Sharma Mathematics [English] Class 11
Chapter 30 Derivatives
Exercise 30.2 | Q 1.14 | Page 25

Video TutorialsVIEW ALL [1]

RELATED QUESTIONS

Find the derivative of `2x - 3/4`


Find the derivative of x–3 (5 + 3x).


Find the derivative of `2/(x + 1) - x^2/(3x -1)`.


Find the derivative of the following function (it is to be understood that a, b, c, d, p, q, r and s are fixed non-zero constants and m and n are integers):

`(px+ q) (r/s + s)`


Find the derivative of the following function (it is to be understood that a, b, c, d, p, q, r and s are fixed non-zero constants and m and n are integers):

`(ax + b)/(px^2 + qx + r)`


Find the derivative of the following function (it is to be understood that a, b, c, d, p, q, r and s are fixed non-zero constants and m and n are integers):

(ax + b)n


Find the derivative of the following function (it is to be understood that a, b, c, d, p, q, r and s are fixed non-zero constants and m and n are integers):

cosec x cot x


Find the derivative of the following function (it is to be understood that a, b, c, d, p, q, r and s are fixed non-zero constants and m and n are integers):

sinn x


\[\frac{1}{x^3}\]


\[\frac{1}{\sqrt{3 - x}}\]


Differentiate  of the following from first principle:

e3x


Differentiate  of the following from first principle: 

− x


Differentiate  of the following from first principle:

sin (x + 1)


Differentiate of the following from first principle:

 x cos x


Differentiate  of the following from first principle:

sin (2x − 3)


Differentiate each of the following from first principle:

\[e^\sqrt{ax + b}\]


Differentiate each of the following from first principle:

\[3^{x^2}\]


tan (2x + 1) 


\[\tan \sqrt{x}\] 


3x + x3 + 33


 log3 x + 3 loge x + 2 tan x


\[\text{ If } y = \left( \sin\frac{x}{2} + \cos\frac{x}{2} \right)^2 , \text{ find } \frac{dy}{dx} at x = \frac{\pi}{6} .\]


\[\text{ If } y = \left( \frac{2 - 3 \cos x}{\sin x} \right), \text{ find } \frac{dy}{dx} at x = \frac{\pi}{4}\]


Find the rate at which the function f (x) = x4 − 2x3 + 3x2 + x + 5 changes with respect to x.


xn tan x 


x2 sin x log x 


(x sin x + cos x ) (ex + x2 log x) 


x5 (3 − 6x−9) 


\[\frac{x}{1 + \tan x}\] 


\[\frac{x \tan x}{\sec x + \tan x}\]


\[\frac{p x^2 + qx + r}{ax + b}\]


Write the value of \[\frac{d}{dx}\left( x \left| x \right| \right)\]


Mark the correct alternative in of the following: 

If \[f\left( x \right) = \frac{x - 4}{2\sqrt{x}}\]

 


Mark the correct alternative in of the following:

If \[y = \sqrt{x} + \frac{1}{\sqrt{x}}\] then \[\frac{dy}{dx}\] at x = 1 is


Mark the correct alternative in of the following:
If \[f\left( x \right) = x^{100} + x^{99} + . . . + x + 1\]  then \[f'\left( 1 \right)\] is equal to 


(ax2 + cot x)(p + q cos x)


Let f(x) = x – [x]; ∈ R, then f'`(1/2)` is ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×