English

If F (X) = X 2 | X | , Write D D X ( F ( X ) )

Advertisements
Advertisements

Question

If f (x) = \[\frac{x^2}{\left| x \right|},\text{ write }\frac{d}{dx}\left( f (x) \right)\] 

Advertisements

Solution

\[\text{ Case } 1: x>0\]
\[\left| x \right| = x\]
\[f\left( x \right) = \frac{x^2}{\left| x \right|} = \frac{x^2}{x} = x\]
\[f'\left( x \right) = 1\]
\[\text{ Case } 2: x<0\]
\[\left| x \right| = - x\]
\[f\left( x \right) = \frac{x^2}{\left| x \right|} = \frac{x^2}{- x} = - x\]
\[f'\left( x \right) = - 1\]
\[\text{ From case 1 and case 2, we have }:\]
`f'(x)={(1, if, x > 0),(-1, if, x < 0):}`

shaalaa.com
  Is there an error in this question or solution?
Chapter 30: Derivatives - Exercise 30.6 [Page 47]

APPEARS IN

R.D. Sharma Mathematics [English] Class 11
Chapter 30 Derivatives
Exercise 30.6 | Q 9 | Page 47

Video TutorialsVIEW ALL [1]

RELATED QUESTIONS

For the function

f(x) = `x^100/100 + x^99/99 + ...+ x^2/2 + x + 1`

Prove that f'(1) = 100 f'(0)


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


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


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):

`cos x/(1 + sin x)`


Find the derivative of the following function at the indicated point:


 x2 + x + 3


 (x2 + 1) (x − 5)


 (x2 + 1) (x − 5)


Differentiate  of the following from first principle:

\[\cos\left( x - \frac{\pi}{8} \right)\]


Differentiate each of the following from first principle:

\[3^{x^2}\]


\[\tan \sqrt{x}\] 


\[\frac{2 x^2 + 3x + 4}{x}\] 


\[\frac{a \cos x + b \sin x + c}{\sin x}\]


a0 xn + a1 xn−1 + a2 xn2 + ... + an1 x + an


\[\log\left( \frac{1}{\sqrt{x}} \right) + 5 x^a - 3 a^x + \sqrt[3]{x^2} + 6 \sqrt[4]{x^{- 3}}\] 


cos (x + a)


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


\[\text{ If } y = \frac{2 x^9}{3} - \frac{5}{7} x^7 + 6 x^3 - x, \text{ find } \frac{dy}{dx} at x = 1 .\] 


x2 ex log 


\[\frac{2^x \cot x}{\sqrt{x}}\] 


x2 sin x log 


(x sin x + cos x) (x cos x − sin x


(1 − 2 tan x) (5 + 4 sin x)


(1 +x2) cos x


(2x2 − 3) sin 


x5 (3 − 6x−9


x−3 (5 + 3x


Differentiate each of the following functions by the product rule and the other method and verify that answer from both the methods is the same.

(3 sec x − 4 cosec x) (−2 sin x + 5 cos x)


\[\frac{x^2 + 1}{x + 1}\] 


\[\frac{2x - 1}{x^2 + 1}\] 


\[\frac{a x^2 + bx + c}{p x^2 + qx + r}\] 


\[\frac{\sqrt{a} + \sqrt{x}}{\sqrt{a} - \sqrt{x}}\] 


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


Write the value of the derivative of f (x) = |x − 1| + |x − 3| at x = 2.


Mark the correct alternative in of the following:

Let f(x) = x − [x], x ∈ R, then \[f'\left( \frac{1}{2} \right)\]


Mark the correct alternative in of the following:

If\[y = 1 + \frac{x}{1!} + \frac{x^2}{2!} + \frac{x^3}{3!} + . . .\]then \[\frac{dy}{dx} =\] 

 


Mark the correct alternative in  of the following:

If\[f\left( x \right) = 1 - x + x^2 - x^3 + . . . - x^{99} + x^{100}\]then \[f'\left( 1 \right)\] 


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 


Mark the correct alternative in each of the following: 

If\[f\left( x \right) = \frac{x^n - a^n}{x - a}\] then \[f'\left( a \right)\] 


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×