EXAMPLE 2
Use
the unit circle
cos θ
=
x
r
=
0
1
= 0
undefined
undefined
cot θ
=
x
y
=
0
–1
tan θ
=
y
x
=
–1
0
sec θ
=
r
x
=
1
0
sin θ
=
y
r
1
=
1
–
= –1
csc θ
=
r
y
=
1
1
–
= –1
= 0