Answer:
cos2θ = -0.5563
tan2θ = -1.49.4
Explanation:
There are 3 trigonometric ratios; Sine, cosine and tangent.
cos = adjacent/hypotenuse
sine = opposite/hypotenuse
tangent = opposite/adjacent
If cosθ = -8/17
θ = cos⁻¹(-8/17)
= cos⁻¹(-0.4706)
= 180+61.9
= 241.9°
cos 2θ = cos (2×241.9)
= cos 483.8° = cos 123.8°
= -0.5563
tan 2θ = tan(2×241.9)
= tan 483.8
= tan 123.8
= -1.49.4