Mister Exam

Derivative of x^2sinxtanx

Function f() - derivative -N order at the point
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The solution

You have entered [src]
 2              
x *sin(x)*tan(x)
x2sin(x)tan(x)x^{2} \sin{\left(x \right)} \tan{\left(x \right)}
(x^2*sin(x))*tan(x)
Detail solution
  1. Apply the product rule:

    ddxf(x)g(x)=f(x)ddxg(x)+g(x)ddxf(x)\frac{d}{d x} f{\left(x \right)} g{\left(x \right)} = f{\left(x \right)} \frac{d}{d x} g{\left(x \right)} + g{\left(x \right)} \frac{d}{d x} f{\left(x \right)}

    f(x)=x2sin(x)f{\left(x \right)} = x^{2} \sin{\left(x \right)}; to find ddxf(x)\frac{d}{d x} f{\left(x \right)}:

    1. Apply the product rule:

      ddxf(x)g(x)=f(x)ddxg(x)+g(x)ddxf(x)\frac{d}{d x} f{\left(x \right)} g{\left(x \right)} = f{\left(x \right)} \frac{d}{d x} g{\left(x \right)} + g{\left(x \right)} \frac{d}{d x} f{\left(x \right)}

      f(x)=x2f{\left(x \right)} = x^{2}; to find ddxf(x)\frac{d}{d x} f{\left(x \right)}:

      1. Apply the power rule: x2x^{2} goes to 2x2 x

      g(x)=sin(x)g{\left(x \right)} = \sin{\left(x \right)}; to find ddxg(x)\frac{d}{d x} g{\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 is: x2cos(x)+2xsin(x)x^{2} \cos{\left(x \right)} + 2 x \sin{\left(x \right)}

    g(x)=tan(x)g{\left(x \right)} = \tan{\left(x \right)}; to find ddxg(x)\frac{d}{d x} g{\left(x \right)}:

    1. Rewrite the function to be differentiated:

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

    2. Apply the quotient rule, which is:

      ddxf(x)g(x)=f(x)ddxg(x)+g(x)ddxf(x)g2(x)\frac{d}{d x} \frac{f{\left(x \right)}}{g{\left(x \right)}} = \frac{- f{\left(x \right)} \frac{d}{d x} g{\left(x \right)} + g{\left(x \right)} \frac{d}{d x} f{\left(x \right)}}{g^{2}{\left(x \right)}}

      f(x)=sin(x)f{\left(x \right)} = \sin{\left(x \right)} and g(x)=cos(x)g{\left(x \right)} = \cos{\left(x \right)}.

      To find ddxf(x)\frac{d}{d x} f{\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)}

      To find ddxg(x)\frac{d}{d x} g{\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)}

      Now plug in to the quotient rule:

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

    The result is: x2(sin2(x)+cos2(x))sin(x)cos2(x)+(x2cos(x)+2xsin(x))tan(x)\frac{x^{2} \left(\sin^{2}{\left(x \right)} + \cos^{2}{\left(x \right)}\right) \sin{\left(x \right)}}{\cos^{2}{\left(x \right)}} + \left(x^{2} \cos{\left(x \right)} + 2 x \sin{\left(x \right)}\right) \tan{\left(x \right)}

  2. Now simplify:

    x(x+xcos2(x)+2tan(x))sin(x)x \left(x + \frac{x}{\cos^{2}{\left(x \right)}} + 2 \tan{\left(x \right)}\right) \sin{\left(x \right)}


The answer is:

x(x+xcos2(x)+2tan(x))sin(x)x \left(x + \frac{x}{\cos^{2}{\left(x \right)}} + 2 \tan{\left(x \right)}\right) \sin{\left(x \right)}

The graph
02468-8-6-4-2-1010-5000050000
The first derivative [src]
/ 2                    \           2 /       2   \       
\x *cos(x) + 2*x*sin(x)/*tan(x) + x *\1 + tan (x)/*sin(x)
x2(tan2(x)+1)sin(x)+(x2cos(x)+2xsin(x))tan(x)x^{2} \left(\tan^{2}{\left(x \right)} + 1\right) \sin{\left(x \right)} + \left(x^{2} \cos{\left(x \right)} + 2 x \sin{\left(x \right)}\right) \tan{\left(x \right)}
The second derivative [src]
/            2                    \              /       2   \                            2 /       2   \              
\2*sin(x) - x *sin(x) + 4*x*cos(x)/*tan(x) + 2*x*\1 + tan (x)/*(2*sin(x) + x*cos(x)) + 2*x *\1 + tan (x)/*sin(x)*tan(x)
2x2(tan2(x)+1)sin(x)tan(x)+2x(xcos(x)+2sin(x))(tan2(x)+1)+(x2sin(x)+4xcos(x)+2sin(x))tan(x)2 x^{2} \left(\tan^{2}{\left(x \right)} + 1\right) \sin{\left(x \right)} \tan{\left(x \right)} + 2 x \left(x \cos{\left(x \right)} + 2 \sin{\left(x \right)}\right) \left(\tan^{2}{\left(x \right)} + 1\right) + \left(- x^{2} \sin{\left(x \right)} + 4 x \cos{\left(x \right)} + 2 \sin{\left(x \right)}\right) \tan{\left(x \right)}
The third derivative [src]
  /             2                    \            /       2   \ /            2                    \      2 /       2   \ /         2   \              /       2   \                             
- \-6*cos(x) + x *cos(x) + 6*x*sin(x)/*tan(x) + 3*\1 + tan (x)/*\2*sin(x) - x *sin(x) + 4*x*cos(x)/ + 2*x *\1 + tan (x)/*\1 + 3*tan (x)/*sin(x) + 6*x*\1 + tan (x)/*(2*sin(x) + x*cos(x))*tan(x)
2x2(tan2(x)+1)(3tan2(x)+1)sin(x)+6x(xcos(x)+2sin(x))(tan2(x)+1)tan(x)+3(tan2(x)+1)(x2sin(x)+4xcos(x)+2sin(x))(x2cos(x)+6xsin(x)6cos(x))tan(x)2 x^{2} \left(\tan^{2}{\left(x \right)} + 1\right) \left(3 \tan^{2}{\left(x \right)} + 1\right) \sin{\left(x \right)} + 6 x \left(x \cos{\left(x \right)} + 2 \sin{\left(x \right)}\right) \left(\tan^{2}{\left(x \right)} + 1\right) \tan{\left(x \right)} + 3 \left(\tan^{2}{\left(x \right)} + 1\right) \left(- x^{2} \sin{\left(x \right)} + 4 x \cos{\left(x \right)} + 2 \sin{\left(x \right)}\right) - \left(x^{2} \cos{\left(x \right)} + 6 x \sin{\left(x \right)} - 6 \cos{\left(x \right)}\right) \tan{\left(x \right)}