Answer :
cosθ = ⁻⁴/₇
cos⁻¹(cosθ) = cos⁻¹(⁻⁴/₇)
θ = 124.8499046
sinθ = sin(124.8499046) = 0.820651806
tanθ = tan(124.8499046) = -1.436140661
cos⁻¹(cosθ) = cos⁻¹(⁻⁴/₇)
θ = 124.8499046
sinθ = sin(124.8499046) = 0.820651806
tanθ = tan(124.8499046) = -1.436140661