Last review problem for midterm. derivative of: (x^2cos(x^3-3x))^(1/4)
is cos(x^3-3x) a product term of a power
or*
the whole thing has a square root of 4 or a power of 1/4
\[\sqrt[4]{x ^{2}(\cos(x ^{3}-3x))}\]
right?
that is correct
apply the chain rule
consider the expression inside the square root as 'u' and differentiate first
any luck ?
Not much so do i start with 1/4(x^2cos(x^3-3x))^(-3/4) for taking the derivative of f(x) first in the chain rule
Then just take that times the derivative of (x^2cos(x^3-3x)) right?
yes... you're right . Now differentiate x^2[cos(x^3-3x)] by using the product rule
so 2x(cos(x^3-3x)+-sin(x^3-3x)((x^3)-3x)x^2
for the second term , you will have to differentiate x^3-3x as well {chain rule applies there as well } .
you've just taken it as it is without differentiating :)
it will be x^2 [ -sin(x^3-3x){d/dx(x^3-3x)}]
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