Apply the product rule:
dxdf(x)g(x)=f(x)dxdg(x)+g(x)dxdf(x)
f(x)=2x; to find dxdf(x):
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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: 2
g(x)=cos(x); to find dxdg(x):
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The derivative of cosine is negative sine:
dxdcos(x)=−sin(x)
The result is: −2xsin(x)+2cos(x)