Find sin `theta` and tan`theta` if `cos theta =-3/5` and `theta` lies in the third quadrant.

Explanation

We have,
`cos^(2)theta + sin^(2)theta=1`
`therefore sintheta +-sqrt(1-cos^(2)theta)`
In the third quadrant, sin `theta` is negative
`=-sqrt(1-(-3/5)^(2))=-4/5`
Now, tan`theta=("sin"theta)/("cos"theta)=-4/5 xx (5/-3)=4/3`