trig problem please help?

3 ⤊

find the exact value of :

sin (-210)

sec(315)

please help, thanks

2007-09-16 08:05:07 · 4 answers · asked by rickyricardoiscool 1 in Science & Mathematics ➔ Mathematics

sin (- 210°) = sin 150° = sin 30° = 1 / 2
sec (315°) = 1 / cos (315°) = 1 / cos 45° = √2

2007-09-16 10:49:35 · answer #1 · answered by Como 7 · 2⤊ 0⤋

sin(-210) = sin 150 = sin 30=1/2

sec 315 = sec 45 = â2

2007-09-16 15:14:52 · answer #2 · answered by chasrmck 6 · 0⤊ 0⤋

sin (-210)
= sin(150)
= sin(30)
= 1/2

sec(315)
= sec(45)
= â2

2007-09-16 15:13:05 · answer #3 · answered by sahsjing 7 · 1⤊ 0⤋

sin(-210) =sin ( -270 + 60) = sin (-3*pi/2 + 60 + 2pi)
= sin(pi/2 + 60) = cos 60 = 1/2

sec(315) = sec(2pi - pi/4)= sec(pi/4) = sqrt(2)

2007-09-16 15:34:54 · answer #4 · answered by mohanrao d 7 · 0⤊ 1⤋