I NEED HELP PLEASE, THANKS! :)

 proof below

Step-by-step explanation:

Use the Difference formula for sin:

  sin (A - B) = sin(A)·cos(B) - cos(A)·sin(B)

sin (180° - θ) = sin(180°)·cos(θ) - cos(180°)·sin(θ)

                    =       0  · cos(θ)    -      -1  · sin(θ)

                    =              0           -           -sin(θ)

                    =                         + sin(θ)

sin (180° - θ) = sin(θ)  

c. (0.6,-1.4)

step-by-step explanation:

hope this