The point (3,-4) is on the terminal side of Ø in standar position.

Question

Which is the sine of ∅?

 

a) -3/5

b) 3/5

c) -4/5

d) 4/5

Answer 1

Consider a triangle with vertices at (0,0), (3,0) and (3,-4)

 

The hypotenuse of this triangle has length sqrt(3^2+4^2)=sqrt(25)=5.

 

So, sin(Θ)=-4/5

 

Choice (c) is correct.

 

 

            3

(0,0)******(3,0)

                    *

     *             *

                    *

        *          *

                    *

          *        *  4

       5           *

             *     *

                    *

                *   *

                 *  *

                   (3,-4)