2/pi*x\ cos |----| \14/5/
cos((pi*x)/(14/5))^2
Let .
Apply the power rule: goes to
Then, apply the chain rule. Multiply by :
Let .
The derivative of cosine is negative sine:
Then, apply the chain rule. Multiply by :
The derivative of a constant times a function is the constant times the derivative of the function.
The derivative of a constant times a function is the constant times the derivative of the function.
Apply the power rule: goes to
So, the result is:
So, the result is:
The result of the chain rule is:
The result of the chain rule is:
Now simplify:
The answer is:
/pi*x\ /pi*x\ -5*pi*cos|----|*sin|----| \14/5/ \14/5/ ------------------------- 7
2 / 2/5*pi*x\ 2/5*pi*x\\ 25*pi *|sin |------| - cos |------|| \ \ 14 / \ 14 // ------------------------------------ 98