the complete question is
find the tan(θ) of an angle in standard position if the terminal side passes through the point (4, -8)
we know that
point (4, -8)----> belong IV quadrant
so
tan(θ) is negative
tan(θ)=opposite side angle θ/adjacent side angle θ
opposite side angle θ=value of the y coordinate
adjacent side angle θ=value of the x coordinate
tan(θ)=-8/4-----> tan(θ)=-2
the answer is
tan(θ)=-2