The equation h = 7 cos(pi/3)t models the height h in centimeters after t seconds of a weight attached to the end of a spring that has been stretched and then released.
a. Solve the equation for t.
b. Find the times at which the weight is first at a height of 1 cm, of 3 cm, and of 5 cm, below the rest position for the second time round your answers to the nearest hundredth

Question

The equation h = 7 cos(pi/3)t models the height h in centimeters after t seconds of a weight attached to the end of a spring that has been stretched and then released.
a. Solve the equation for t.
b. Find  the times at which the weight is first at a height of 1 cm, of 3 cm, and of 5 cm, below the rest position for the second time round your answers to the nearest hundredth

anonymous · Answer

a. Leave 't' on one side by using inverse cos fn.
b. Put h = 1,3,5 and get values of 't'.

anonymous · Answer

so for a i just put h/7 = cos (pi/3t) 3h/7 cos pi = t Right?

anonymous · Answer

I did not get you properly, but I meant this.
$$\frac{ h }{ 7 }= \cos(\pi/3)t$$
$$t = \frac{ 3 }{ \pi } \cos^{-1} \frac{ h }{ 7 }$$