If 15 cot A = 8, find sin A and sec A. [2 Marks]
Let us draw a right triangle ABC, right angled at B.
It is given that: 15 cot A = 8
cot A=815=ABBC
\( \sum \)
Let, AB = 8K, BC = 15K
Using Pythagoras theorem, we have
AC2=AB2+BC2=(8K)2+(15K)2=64K2+225K2=289K2∴ AC=17K [1 Mark]
∴ sin A=BCAC=15K17K=1517, and
sec A=ACAB=17K8K=178 [1 Mark]