Sum and Difference of Trig Identities

Write the following expression as the sine, cosine, or tangent of an angle.
cos(175)cos(55)+sin(175)sin(55)

• sin(120)
• cos(120)
• cos(230)
• sin(230)

Tags

CCSS.HSF.TF.C.9

Use Sum or Difference Identities to find the exact value of each expression.
cos(75°)

• 1/4
• √6/4 - √2 / 4
• √6 + √2 / 4
• -√6/4 - √2 / 4

Tags

CCSS.HSF.TF.C.9

sin 105º

• √3/2
• -1/4(√2 + √6)
• 1/4 (√2 + √6)
• 2-√3

Tags

CCSS.HSF.TF.C.9

Please choose the correct sum and difference formula:
cos (α-β) =

• sin α cos β + cos α sin β
• sin α cos β - cos α sin β
• cos α cos β - sin α sin β
• cos α cos β + sin α sin β

Tags

CCSS.HSF.TF.C.9

Find the exact value of the expression.
cos(20)cos(40) - sin(20)sin(40)

• 1/4
• 1/2
• √(3)/2
• √(3)

Tags

CCSS.HSF.TF.C.9

Find the exact value of the expression.
sin(5π/12)cos(π/4) - cos(5π/12)sin(π/4)

• 1/2
• -1/2
• -√(2)/2
• √(3)/2

Tags

CCSS.HSF.TF.C.9

Given sin α = -3/5, cos α = -4/5 and cos β = (2√5)/5, sin β = (-√5)/5
Please find the sum or difference:
cos (α+β)=

• (-11√5)/25
• (-2√5)/25
• (√2-√6)/4
• 2

Tags

CCSS.HSF.TF.C.9

Given sin α = -3/5, cos α = -4/5 and cos β = (2√5)/5, sin β = (-√5)/5
Please find the sum or difference:
sin (α-β)=

• 0
• (-10√5)/25
• (√2-√6)/4
• (√8)/4

Tags

CCSS.HSF.TF.C.9

Simplify
sin(x+π)

• -1
• csc(x)
• sin(x)
• -sin(x)

Tags

CCSS.HSF.TF.C.9

Find the exact value.
cos (5π/18 - π/9)

• √(3)/2
• 1/4
• 1/2
• 1

Tags

CCSS.HSF.TF.C.9