5 - NCETM
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5. AB is the diameter of the circle, centre O. TP is a tangent to the circle at the point P. ABT is a straight line. P y T B x O A Angle BAP = x and angle BTP = y. Show that y = 90 – 2x. You must explain clearly how you obtain your answer. .................................................................................................................................. ............. .................................................................................................................................. ............. .................................................................................................................................. ............. .................................................................................................................................. ............. .................................................................................................................................. ............. .................................................................................................................................. ............. .................................................................................................................................. ............. .................................................................................................................................. ............. .................................................................................................................................. ............. .................................................................................................................................. ............. .................................................................................................................................. ............. (Total 4 marks) 1. Angle APB = 90 B1 or angle APB = 90 Angle PBA = 90 – x or angle PBT = 90 + x B1 Angle TBP = x B1 or angle TBP = x x + y = 90 – x B1dep or x + y+ 90 + x = 180 for B4 must see logical progression from x to y [4]
