In Fig. 8.13, find tan P – cot R.

Applying Pythagoras theorem for ΔPQR, we obtain


PR2 = PQ2 + QR2


(13 cm)2 = (12 cm)2 + QR2


169 cm2 = 144 cm2 + QR2


25 cm2 = QR2


QR = 5 cm


tan P =


=


cot R =


=


tan P - cot R =


= 0


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