Trigonometric Identities Review

Identities

100

1 / (sin x)

What is csc x?

200

(sin x) / (cos x)

What is tan x?

300

1 / (sec x)

What is cos x?

400

(cos x) / (sin x)

What is cot x?

500

cos (-x)

What is cos x?

Simplifying Identities

100

(sec x)(cos x)

What is 1?

200

(tan x)(cos x)

What is sin x?

300

(sec x) / (tan x)

What is csc x?

400

sin x (csc x - sec x)

What is 1 - tan x?

500

csc x - sin x

What is (cos²x) / (sin x) or (cos x)(cot x) ?

Pythagorean Identities

100

sin²x + cos²x

What is 1?

200

1 + cot²x

What is csc²x?

300

1 - cos²x

What is sin²x?

400

sec²x - 1

What is tan²x?

500

(1 + csc x)(1 - csc x)

What is -cot²x ?

Verifying Identities

100

cos²x + tan²x * cos²x = 1

sin²x = sin²x

200

1 = tanx * cosx * cscx

1 = 1

300

cos²x + tan²x * cos²x = 1

cos²x + sin²x = 1

400

cot²x * sec²x = csc²x

cot²x + 1 = csc²x

500

sinx * tanx = secx - cosx

1-cos²x        1-cos²x

---------  =   ---------

cosx              cosx