1. The basic identity is Cot θ = cos θ csc θ, where the domain of validity is all values of θ except where sin θ = 0.
2. tan θ + cot θ = (1 / sin θ cos θ)
= (sin θ / cos θ) + (cos θ / sin θ)
= (sin^2 θ + cos^2 θ) / (sin θ cos θ)
= 1 / (sin θ cos θ)
3.
a. To solve the equation h = 7cos(π/3 t) for t, we need to isolate t.
Divide both sides by 7: cos(π/3 t) = h/7
Take the inverse cosine of both sides: π/3 t = arccos(h/7)
Multiply by 3/π: t = 3/π * arccos(h/7)
b.
- At a height of 1 cm:
t = 3/π * arccos(1/7) ≈ 1.16 seconds
- At a height of 3 cm:
t = 3/π * arccos(3/7) ≈ 1.87 seconds
- At a height of 5 cm:
t = 3/π * arccos(5/7) ≈ 2.31 seconds