Question

Value of cos p where PQ=12cm and PR=13cm

Answer 1

Answer:

In the figure, by Pythagoras Theorem,

QR

2

=PR

2

−PQ

2

=(13)

2

−(12)

2

=25

⇒QR=

25

=5 cm

In △PQR right angled at Q,

QR=5 cm is side opposite to the angle P and PQ=12 cm is side adjacent to the angle P.

Therefore, tanP=

PQ

QR

=

12

5

Now, QR=5 cm is side adjacent to the angle R and PQ=12 cm is side opposite to the angle R.

Therefore, cotR=

PQ

QR

=

12

5

.

Hence, tanP−cotR=

12

5

−

12

5

=0