Question

1. cosx--lies in third quadrant.

Answer 1

Given trigonometric function is,

cosx=− 1 2

Write the expression of Pythagorean identity.

cos 2 x+ sin 2 x=1

Substitute the value of cosx .

( − 1 2 ) 2 + sin 2 x=1 sin 2 x=1− 1 4 sin 2 x= 3 4 sinx=± 3 2

For third quadrant, sinx=− 3 2

Write the expression of reciprocal relation.

secx= 1 cosx secx= 1 − 1 2 secx=−2

Write the expression of reciprocal relation.

cosecx= 1 sinx cosecx= 1 − 3 2 cosecx=− 2 3

Write the expression for tanx .

tanx= sinx cosx tanx= − 3 2 − 1 2 tanx= 3

Write the expression of reciprocal relation.

cotx= 1 tanx cotx= 1 3