#1**+3 **

First one....

Note at 0 sec, height = 0

At 1.5 sec...it has reached its highest point and returns to its resting position

At 3.0....it has reached its lowest point and back to its resting position

So....3 seconds

Second one

At 0.5 seconds....it's at the resting position

At 1 sec...it reaches its highest point

At 1.5 sec...it is back at the resting position

So 1.5 - 0.5 = 1 second

Third one

March means that x = 3

So.....12.2 cos (3.14 * 3 / 6) + 54.9 = 54.9°

Last one

The minimum value for the cosine is -1

So....the lowest temperature is

23.7 (-1) + 18 = -5.7°

CPhill Feb 13, 2019