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sqrt(cos^2x-sin^2x)

Derivative of sqrt(cos^2x-sin^2x)

Function f() - derivative -N order at the point
v

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The solution

You have entered [src]
   ___________________
  /    2         2    
\/  cos (x) - sin (x) 
sin2(x)+cos2(x)\sqrt{- \sin^{2}{\left(x \right)} + \cos^{2}{\left(x \right)}}
  /   ___________________\
d |  /    2         2    |
--\\/  cos (x) - sin (x) /
dx                        
ddxsin2(x)+cos2(x)\frac{d}{d x} \sqrt{- \sin^{2}{\left(x \right)} + \cos^{2}{\left(x \right)}}
Detail solution
  1. Let u=sin2(x)+cos2(x)u = - \sin^{2}{\left(x \right)} + \cos^{2}{\left(x \right)}.

  2. Apply the power rule: u\sqrt{u} goes to 12u\frac{1}{2 \sqrt{u}}

  3. Then, apply the chain rule. Multiply by ddx(sin2(x)+cos2(x))\frac{d}{d x} \left(- \sin^{2}{\left(x \right)} + \cos^{2}{\left(x \right)}\right):

    1. Differentiate sin2(x)+cos2(x)- \sin^{2}{\left(x \right)} + \cos^{2}{\left(x \right)} term by term:

      1. Let u=cos(x)u = \cos{\left(x \right)}.

      2. Apply the power rule: u2u^{2} goes to 2u2 u

      3. Then, apply the chain rule. Multiply by ddxcos(x)\frac{d}{d x} \cos{\left(x \right)}:

        1. The derivative of cosine is negative sine:

          ddxcos(x)=sin(x)\frac{d}{d x} \cos{\left(x \right)} = - \sin{\left(x \right)}

        The result of the chain rule is:

        2sin(x)cos(x)- 2 \sin{\left(x \right)} \cos{\left(x \right)}

      4. The derivative of a constant times a function is the constant times the derivative of the function.

        1. Let u=sin(x)u = \sin{\left(x \right)}.

        2. Apply the power rule: u2u^{2} goes to 2u2 u

        3. Then, apply the chain rule. Multiply by ddxsin(x)\frac{d}{d x} \sin{\left(x \right)}:

          1. The derivative of sine is cosine:

            ddxsin(x)=cos(x)\frac{d}{d x} \sin{\left(x \right)} = \cos{\left(x \right)}

          The result of the chain rule is:

          2sin(x)cos(x)2 \sin{\left(x \right)} \cos{\left(x \right)}

        So, the result is: 2sin(x)cos(x)- 2 \sin{\left(x \right)} \cos{\left(x \right)}

      The result is: 4sin(x)cos(x)- 4 \sin{\left(x \right)} \cos{\left(x \right)}

    The result of the chain rule is:

    2sin(x)cos(x)sin2(x)+cos2(x)- \frac{2 \sin{\left(x \right)} \cos{\left(x \right)}}{\sqrt{- \sin^{2}{\left(x \right)} + \cos^{2}{\left(x \right)}}}

  4. Now simplify:

    sin(2x)cos(2x)- \frac{\sin{\left(2 x \right)}}{\sqrt{\cos{\left(2 x \right)}}}


The answer is:

sin(2x)cos(2x)- \frac{\sin{\left(2 x \right)}}{\sqrt{\cos{\left(2 x \right)}}}

The graph
02468-8-6-4-2-10105-5
The first derivative [src]
   -2*cos(x)*sin(x)   
----------------------
   ___________________
  /    2         2    
\/  cos (x) - sin (x) 
2sin(x)cos(x)sin2(x)+cos2(x)- \frac{2 \sin{\left(x \right)} \cos{\left(x \right)}}{\sqrt{- \sin^{2}{\left(x \right)} + \cos^{2}{\left(x \right)}}}
The second derivative [src]
  /                         2       2   \
  |   2         2      2*cos (x)*sin (x)|
2*|sin (x) - cos (x) - -----------------|
  |                       2         2   |
  \                    cos (x) - sin (x)/
-----------------------------------------
             ___________________         
            /    2         2             
          \/  cos (x) - sin (x)          
2(sin2(x)cos2(x)2sin2(x)cos2(x)sin2(x)+cos2(x))sin2(x)+cos2(x)\frac{2 \left(\sin^{2}{\left(x \right)} - \cos^{2}{\left(x \right)} - \frac{2 \sin^{2}{\left(x \right)} \cos^{2}{\left(x \right)}}{- \sin^{2}{\left(x \right)} + \cos^{2}{\left(x \right)}}\right)}{\sqrt{- \sin^{2}{\left(x \right)} + \cos^{2}{\left(x \right)}}}
The third derivative [src]
  /             2                   2                2       2     \              
  |        3*cos (x)           3*sin (x)        6*cos (x)*sin (x)  |              
4*|2 - ----------------- + ----------------- - --------------------|*cos(x)*sin(x)
  |       2         2         2         2                         2|              
  |    cos (x) - sin (x)   cos (x) - sin (x)   /   2         2   \ |              
  \                                            \cos (x) - sin (x)/ /              
----------------------------------------------------------------------------------
                                 ___________________                              
                                /    2         2                                  
                              \/  cos (x) - sin (x)                               
4(2+3sin2(x)sin2(x)+cos2(x)3cos2(x)sin2(x)+cos2(x)6sin2(x)cos2(x)(sin2(x)+cos2(x))2)sin(x)cos(x)sin2(x)+cos2(x)\frac{4 \cdot \left(2 + \frac{3 \sin^{2}{\left(x \right)}}{- \sin^{2}{\left(x \right)} + \cos^{2}{\left(x \right)}} - \frac{3 \cos^{2}{\left(x \right)}}{- \sin^{2}{\left(x \right)} + \cos^{2}{\left(x \right)}} - \frac{6 \sin^{2}{\left(x \right)} \cos^{2}{\left(x \right)}}{\left(- \sin^{2}{\left(x \right)} + \cos^{2}{\left(x \right)}\right)^{2}}\right) \sin{\left(x \right)} \cos{\left(x \right)}}{\sqrt{- \sin^{2}{\left(x \right)} + \cos^{2}{\left(x \right)}}}
The graph
Derivative of sqrt(cos^2x-sin^2x)