Precalculus Trig Identities

Simplify:  tanxcotx-cos²x

• tanx
• cotx
• sin²x
• cos²x

Simplify this to a basic trigonometry function:
tan(x)csc(x) 

• tanx
• secx
• cotx
• cscx

True or False, (cot(x)) / (sec(x)) = sin(x)?

• True

• False

True or False, cos(x)/tan(x) = cot(x)cos(x)

• True

• False

When verifying you must first ...

• pick a side to simplify 
• find a trig. identity 
• Change to sine and cosine
• Change Values

Simplify

• sinθ

• cos²θ

• sin²θ

• 1- sin²θ

• csc²θ
• csc θ sec θ
• cot θ tan θ
• 1/sinθ

Simplify:

(secx-1)(secx+1).

• tan²x

• sinx

• cot²x

• cosx

Sine means

• opposite / hypotenuse

• adjacent / hypotenuse

• opposite / adjacent

• adjacent / opposite

Verify the following.
tanB (cotB + tanB) = sec²B

• 1+ tan²B
• sec²B
• cot²B
• tan²B