Trigonometry help needed?

Question

Calculate  2cot 10°(1/sin20° - cot 20°)

Answer 1

2 * cot(10) * (1/sin(20) - cot(20)) =>

2 * (cos(10)/sin(10)) * (1/sin(20) - cos(20)/sin(20)) =>

2 * (cos(10)/sin(10)) * ((1 - cos(20)) / sin(20)) =>

2 * cos(10) * (1 - cos(20)) / (sin(10) * sin(20)) =>

2 * cos(10) * (1 - (cos(10)^2 - sin(10)^2)) / (sin(10) * 2 * sin(10) * cos(10)) =>

2 * cos(10) * (1 - cos(10)^2 + sin(10)^2) / (2 * sin(10)^2 * cos(10)) =>

2 * cos(10) * (sin(10)^2 + sin(10)^2) / (2 * sin(10)^2 * cos(10)) =>

2 * 2 * cos(10) * sin(10)^2 / (2 * sin(10)^2 * cos(10)) =>

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Answer 2

2cot 10°(1/sin20° - cot 20°)

just plug the numbers into your calculator

11.34256(2.923804 - 2.747477)

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