What is the measure of the circumference of d

An objects motion is described by the equation d= 4sin (pi t) what will the height of the object be at 1.75 seconds?

[10 points, algebra 2]according to my answer key the restrictions are -1 and 4. but why not positive 1?

Click an item in the list or group of pictures at the bottom of the problem and, holding the button down, drag it into the correct position in the answer box. release your mouse button when the item is place. if you change your mind, drag the item to the trashcan. click the trashcan to clear all your answers. solve this quadratic equation using the quadratic formula. 2x2 - 2x=1 need asap