Question

what is the value of
sec840° , cot (-945°) , sin 600° and tan (-690°).
​

Answer 1

Step-by-step explanation:

sec 840°

=sec ( 8 × 90 + 120)

= sec ( 2×360 +120)

= sec 120

= sec( 90 + 30)

= -cosec 30°

= -2

cot ( -945)

=-cot (2×360+225)

= -cot(225)

= - cot (180+45)

= -cot ( 45)

= -1

sin 600

= sin ( 360 + 240)

= sin ( 180+60)

= -sin (60)

= -√3/2

tan ( -690)

= - tan ( 2×360 -30)

= -(-tan 30)

= tan 30

= 1/√3

{refer to ssc 11 class maths textbook }