Wednesday, 2 March 2016

trigonometry - Circle with cyclic quadrilateral angles with tangent




I am trying to answer the following questions. As you can see, I have done the first part but cannot make headway with the second part.



PTQ is the tangent to a circle at the point T. The points A and B on the circumference of the circle are such that TA and TB make acute angles α and β with TP and TQ respectively. If AB meets the diameter through T at N, prove that TN = asinαsinβcos(αβ), where a is the length of the diameter.
If the points C and D on the circumference of the circle are such that TC and TD make acute angles γ and δ with TP and TQ respectively and CD meets the diameter through T at the same point N, prove that tanαtanβ=tanγtanδ



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Answer



Here is my final working for the problem
enter image description here



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