[" 20.(a) "tan3x],[" (b) "cot3x]

(d) / (dx) [((tan ^ (2) 2x-tan ^ (2) x) / (1-tan ^ (2) 2x tan ^ (2) x)) cot3x] =

(1)/(tan 3x- tanx)-(1)/( cot 3 x- cot x)=

Solve: tan x = 3cot x .

tan3x =-cot[x+pi/6]

If A+B+C=pi , prove that (a) tan 3A+tan3B+tan3C=tan3A tan 3B tan 3C (b) cot""(A)/(2)+cot""(B)/(2)+cot""(C)/(2)=cot""(A)/(2)cot""(B)/(2)cot""(C)/(2)

For all real values of x, cot x-2cot2x is equal to tan2x b.tan x c.cot3x d.none of these

For all real values of x ,cotx-2cot2x is equal to a. tan2x b. t a n x c. cot3x d. none of these

Local min.of a tan x+b cot x

tan x+3 cot x-5 secx