Trig

secθ

cotθ

ALSO EQUAL TO cosθ/sinθ

tanθ

cscθ

sin0

0/r = 0

cos0

x/r = x/x = 1

tan0

0/x

csc0

undefined

sec0

r/x = x/x = 1

cot0

undefined

sin90

1

sin180

0

sin270

-1

cos90

undefined

cos180

-1

cos270

0

tan90

undefined

tan180

0

tan270

undefined

csc90

1

csc180

undefined

csc270

-1

sec90

undefined

sec180

-1

sec270

undefined

cot90

0

cot180

undefined

cot270

0

Pythagorean identities

cos²t + sin²t = 1

1 + tan²t = sec²

1 + cot²t = csc²t