Question

What value for function y=3cos(t-pi) + 2 gives an instantaneous rate of change of 0?

a) 0
b) pi/2
c) pi/3
d) pi/4

Answer 1

pi/3

Answer 2

dy/dx = -3 sin(t-π)

=0
sin(t-π) = 0
t-π = 0 , or t-π = π or t-π = 2π

t = ... -3π, -2π, -π , 0 , π, 2π , 3π . .

Answer 3

Answer is 0, right?