9" tan "240

( tan (-225 ^@)tan (570 ^@)sec (675 ^@))/( cot (135^@ ) tan ( 240 ^@2 ) coscec (-45^@ )) is

Find the values: (ii) sin 135^(@) cos 210^(@) tan 240^(@) cot 300^@ "sec" 330^(@)

Evaluate, tan240^@.

Prove that : tan 13A-tan 9A- tan 4A= tan 13A tan 9A tan 4A .

Prove that tan13x = tan 4x + tan 9x + tan 4x tan 9x tan 13x

Prove tan 9^@. tan 21^@.tan 69^@.tan 81^@=1

Prove that : tan 9^@- tan 27^@- tan 63^@ + tan 81^@ = 4 .

The value of tan 9^@ - tan 27^@ - tan 63^@ + tan 81^@ is equal to:

Prove that : (i) "tan"3A-"tan"2A-"tan"A="tan"3A "tan"2A "tan"A (ii) "tan"7A-"tan"5A-"tan"2A="tan"7A "tan"5A "tan"2A (iii) "tan"13 A -"tan" 9A-"tan" 4A ="tan"13 A "tan"9A tan 4A.