Question

Given tantheta = 4/3 and pi < theta < 3pi/2; find cos2theta

Answer 1

Answer:

d. -7/25

Step-by-step explanation:

π<θ<3π/2  in third quadrant

tanθ = 4/3

sinθ = - 4/5

cosθ = - 3/5

cos 2θ = cos²θ - sin²θ = (- 3/5)² - (- 4/5)² = 9/25 - 16/25 = - 7/25

Answer 2

Answer:

D

Step-by-step explanation:

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