It was complicated but I did it
.15(pi)=24-68(0) that is the answer hope it helps
well, let's split the hours in minutes, so since 1 hr is 60 minutes, so he can walk 2.833 miles in 60 minutes, well, 3 hrs is 3*60 = 180 minutes, then we add 15 minutes, that's 195 minutes.
if he can walk 2.833 miles in 60 minutes, how long will it be for 195 minutes?
Sin2x=2sinxcosx, cos2x=1-2sin^2x
sin(2x)+cos(3x)=2sinxcosx+cos(x+2x)
cos(x+2x)=cosx(1-2sin^2(x))-sinx2sinxcosx
sin(2x)+cos(3x)=2sinxcosx(1-sinx)+cosx(1-2sin^2(x))