Question

the value of sec(-855°) is​

Answer 1

sec (– 855°) = sec 855°

= sec (720° + 135°)

= sec (2 x 360° + 135°)

= sec 135°

= sec (90° + 45°)

= – cosec 45°

= -√2

Answer 2

Answer:

sec(-855°) = -√2

Step-by-step explanation:

sec(-855°) =1/cos(-855°)

since cos(-x) = cos(x)

sec(-855°) = 1/cos(855°)

=1/cos(2*360° + 135°)

=1/cos(135°)

= 1/ (-cos 45°)

[cos(x) is negative in second quadrant ]

= 1/(-1/√2)

= -√2