The position of an object moving along a line is given by p(t) = t - tsin(( pi )/4t) . What is the speed of the object at t = 4 ?

1 Answer
May 17, 2016

v(4)=1+pi

Explanation:

v(t)=d/(d t) p(t)

v(t)=d/(d t) (t-t sin(pi/4 t))

v(t)=1-(1*sin(pi/4 t)+t*pi/4cos(pi/4 t))

v(4)=1-(sin(pi/4*4)+4*pi/4*cos(pi/4*4))

v(4)=1-(sin pi+pi*cos pi)

sin pi=0
cos pi=-1

v(4)=1-(0-pi)

v(4)=1+pi