a particle moves along the x-axis and its position for time >= 0 is x(t)=cos(2t) +sec t. when t= pie, the accelleration of the particle is?

Answer 1

x(t) = cos(2t)+sec(t)

x'(t) = -2sin(2t) + sec(t)tan(t)

a(t) = x"(t) = -4cos(2t) + sec(t)tan(t)tan(t) + sec(t)sec²(t)

= -4cos(2t) + sec(t)tan²(t) + sec³(t)

a(π) = -4 + 0 + (-1)³ = -5