Question

Please help me!!! Will give brainliest and 12 points! Topic is Pythagorean identity find values

Answer 1

Answer:

cos θ = -(√3)/2

tan θ = -1/√3

Step-by-step explanation:

$\frac{\pi }{2} <\theta <\pi \ \ \ sin \ \theta = \frac{1}{2}$

Part A: find cos θ:

Using Pythagorean identity

sin²θ + cos²θ = 1

cos²θ = 1 - sin²θ = 1 - (1/2)² = 1 - 1/4 = 3/4

cos θ = ±√(3/4) = ±(√3)/2

∵(π/2) < θ < π  ⇒ ∴ cos θ = -(√3)/2

Part B: find tan θ:

sec θ = 1/(cos θ) = -2/√3

Using Pythagorean identity

tan²θ + 1 = sec²θ

tan²θ = sec²θ - 1 = 4/3 - 1 = 1/3

tan θ = ±√(1/3) = ± 1/√3

∵(π/2) < θ < π  ⇒ ∴ tan θ = -1/√3