Sum Difference and Double Angle Formulas

Use a sum or difference formula to find an exact value of sin 105º

Use a double-angle identity to find the exact value of each expression cos θ = 4/5 and 270° < θ < 360° Find sin 2θ

Given tan α = 3/4 and tan β = (-1/2)

Please find the sum and difference:

tan (α-β)=

• 2

• A
• B
• C
• D

Using the second identity, find Cos(50)

• sin²(25) - cos²(25) 

• cos²(50) - sin²(50)

• cos²(25) - sin²(25)

• sin²(50) - cos²(50) 

Simplify using double angle identities

• A

• B

• C

• D

Using the first identity, find Sin(180)

• 2sin(90)cos(90)

• 2sin(180)cos(180)

• sin(90)cos(90)

• sin(180)cos(180)

If A and B are first quadrant angles with sinA=15/17 and cosB=4/5, find cos(A - B).

• 3/8

• 8/17

• -13/85

• 77/85

• cos(32°)

• cos(60°)

• sin(32°)

• sin(60°)