Apply the quotient rule, which is:
dxdg(x)f(x)=g2(x)−f(x)dxdg(x)+g(x)dxdf(x)
f(x)=sin((8x2+3x)+4) and g(x)=cos((8x2+3x)+4).
To find dxdf(x):
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Let u=(8x2+3x)+4.
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The derivative of sine is cosine:
dudsin(u)=cos(u)
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Then, apply the chain rule. Multiply by dxd((8x2+3x)+4):
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Differentiate (8x2+3x)+4 term by term:
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Differentiate 8x2+3x term by term:
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The derivative of a constant times a function is the constant times the derivative of the function.
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Apply the power rule: x2 goes to 2x
So, the result is: 16x
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The derivative of a constant times a function is the constant times the derivative of the function.
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Apply the power rule: x goes to 1
So, the result is: 3
The result is: 16x+3
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The derivative of the constant 4 is zero.
The result is: 16x+3
The result of the chain rule is:
(16x+3)cos((8x2+3x)+4)
To find dxdg(x):
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Let u=(8x2+3x)+4.
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The derivative of cosine is negative sine:
dudcos(u)=−sin(u)
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Then, apply the chain rule. Multiply by dxd((8x2+3x)+4):
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Differentiate (8x2+3x)+4 term by term:
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Differentiate 8x2+3x term by term:
-
The derivative of a constant times a function is the constant times the derivative of the function.
-
Apply the power rule: x2 goes to 2x
So, the result is: 16x
-
The derivative of a constant times a function is the constant times the derivative of the function.
-
Apply the power rule: x goes to 1
So, the result is: 3
The result is: 16x+3
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The derivative of the constant 4 is zero.
The result is: 16x+3
The result of the chain rule is:
−(16x+3)sin((8x2+3x)+4)
Now plug in to the quotient rule:
cos2((8x2+3x)+4)(16x+3)sin2((8x2+3x)+4)+(16x+3)cos2((8x2+3x)+4)