Can someone figure out the answer to this

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

Adrawer contains 12 identical white socks, 18 identical black socks and 14 identical brown socks. what is the least number of socks you must choose, without looking, to be certain that you have chosen two socks of the same colour?

What expression is equivalent to log3(x+4)