How do I find the value of sec -3pi/4?

Question

12720 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2015-08-22T12:52:22

#sec((-3pi)/4) = -sqrt(2)#

#sec = ("hypothenuse")/("adjacent side")#
enter image source here

Answer 2 · 2015-08-22T23:39:09

Find #sec ((-3pi)/4)#

Ans: #- sqrt2#

Another way to find #sec((-3pi)/4)#

#sec ((-3pi)/4) = 1/sin ((-3pi)/4).# Find #sin ((-3pi)/4)#

On the trig unit circle,
#sin ((-3pi)/4) = sin (-pi/4) = - sin (pi/4) = - sqrt2/2#
Therefor:
#sec ((-3pi)/4) = (1/sin) = -2/sqrt2 = - sqrt2#