1 --------- 2 cos (x)*x
1/(cos(x)^2*x)
Let .
Apply the power rule: goes to
Then, apply the chain rule. Multiply by :
Apply the product rule:
; to find :
Let .
Apply the power rule: goes to
Then, apply the chain rule. Multiply by :
The derivative of cosine is negative sine:
The result of the chain rule is:
; to find :
Apply the power rule: goes to
The result is:
The result of the chain rule is:
Now simplify:
The answer is:
1 / 2 \
---------*\- cos (x) + 2*x*cos(x)*sin(x)/
2
x*cos (x)
-----------------------------------------
2
x*cos (x)
/ 2 2 \
/ 1 2*sin(x)\ -cos(x) + 2*x*sin(x) 2*\x*cos (x) - x*sin (x) + 2*cos(x)*sin(x)/ 2*(-cos(x) + 2*x*sin(x))*sin(x)
|- - + --------|*(-cos(x) + 2*x*sin(x)) - -------------------- + ------------------------------------------- + -------------------------------
\ x cos(x) / x cos(x) cos(x)
----------------------------------------------------------------------------------------------------------------------------------------------
2 3
x *cos (x)
/ 1 2*sin(x)\ / 1 2*sin(x)\ / 2 2 \ / 1 2*sin(x)\
/ 2 2 \ / 2 \ |- - + --------|*(-cos(x) + 2*x*sin(x)) / 2 2 \ 2*|- - + --------|*\x*cos (x) - x*sin (x) + 2*cos(x)*sin(x)/ 2 / 2 2 \ 2*|- - + --------|*(-cos(x) + 2*x*sin(x))*sin(x)
2*\- 3*cos (x) + 3*sin (x) + 4*x*cos(x)*sin(x)/ | 1 3*sin (x) 2*sin(x)| 3*(-cos(x) + 2*x*sin(x)) \ x cos(x) / 6*\x*cos (x) - x*sin (x) + 2*cos(x)*sin(x)/ \ x cos(x) / 10*sin (x)*(-cos(x) + 2*x*sin(x)) 12*\x*cos (x) - x*sin (x) + 2*cos(x)*sin(x)/*sin(x) 8*(-cos(x) + 2*x*sin(x))*sin(x) \ x cos(x) /
-2*cos(x) - ----------------------------------------------- + 2*(-cos(x) + 2*x*sin(x))*|1 + -- + --------- - --------| + ------------------------ + 4*x*sin(x) - --------------------------------------- - ------------------------------------------- + ------------------------------------------------------------ + --------------------------------- + --------------------------------------------------- - ------------------------------- + ------------------------------------------------
cos(x) | 2 2 x*cos(x)| 2 x x*cos(x) cos(x) 2 2 x*cos(x) cos(x)
\ x cos (x) / x cos (x) cos (x)
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
2 3
x *cos (x)