Review for chapter 2 and 4

Given sin α = -3/5, cos α = -4/5 and cos β = (2√5)/5, sin β = (-√5)/5 Please find cos(a + b)

(-11√5)/25

(1 - csc^2(x))tan^2(x)

-1

(tan 8π/9-tan π/18)/(1+tan 8π/9 tan π/18)

-√3/3

Simplify: (sin^2(θ))(1 + cot^2(θ))

1

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

1/2

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

1/2

sinθcos3θ+cosθsin3θ

4θ

Solve on the interval [0,360) 2cosx-1=0

60, 300

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

cos(120)

.(sec^2(x)- 1)/sin^2(x)

sec^2(x)

(tan u+tan 4u)/(1-tan u tan 4u)

tan 5u

Simplify: (sec(θ) + 1)(sec(θ) - 1)

tan^2(θ)

Solve sinθ = -1 on θ∈[0, 2π)

θ = 3π /2

Solve cosθ = - √(3)/2 on θ∈[0, 2π)

θ = 5π /6, 7π /6

cos(10)cos(35)-sin(10)sin(35)

√2/2

sinπ/9*cos2π/9+cosπ/9*sin2π/9

√3/2