Question
If f(x)=5cos(2ln(x)), find f'(x).
My answer is (-5sinx)(2lnx)+(5cosx)(1/x)
I just did the product rule
can you verify if this is correct please!
My answer is (-5sinx)(2lnx)+(5cosx)(1/x)
I just did the product rule
can you verify if this is correct please!
Answers
no, I think MathMate did the same question a bit back but I can't find it.
You don't have a product
think of (2lnx) as the "angle"
how about letting p = 2lnx
then y = 5cos(p)
and dy/dx = -5sin(p)dp/dx
but dp/dx = 2/x
so dy/dx = -5sin(p)(2/x)
= -5sin(2lnx)(2/x)
= (-10/x)(sin(2lnx))
You don't have a product
think of (2lnx) as the "angle"
how about letting p = 2lnx
then y = 5cos(p)
and dy/dx = -5sin(p)dp/dx
but dp/dx = 2/x
so dy/dx = -5sin(p)(2/x)
= -5sin(2lnx)(2/x)
= (-10/x)(sin(2lnx))
Related Questions
How do I solve these?
1) 2sinxcosx-cosx=0
2) cos^2(x)-0.5cosx=0
3) 6sin^2(x)-5sinx+1=0
4) tan^...
what is the polar area between r=5sinx and r=5cosx
Express each of the following in the form Rsin(x+a), where r>0 and 0< a <2pi
(a) 5cosx + 12sin...
Using the Quotient Rule of Logarithms, the Product Rule of Logarithms, and the Power Rule of Logarit...