Let f(x)={−x2if x≥0,x+8if x<0.
Compute f(f(f(f(f(1))))).
f(1)=-1
y=−x2, and y=1
1=−x2, solve for x, x=−1, check it fits piecewise, and it does.
therefore f(1)=−1
You can also graph the equations y=−x2 with x≥0 and y=x+8 with x<0, go to where y=1 and see what x is.
f(1) = - (1)^2 = -1
f (f(1) ) = f (-1) = -1 + 8 = 7
f (f (f (1) ) ) = f ( 7) = - (7)^2 = -49
f ( f ( f( f(1) ) ) ) = f (-49) = -49 + 8 = -41
f ( f ( f ( f ( f ( 1) ) ) ) ) = f (-41) = - (-41)^2 = -1681