Please help how do you solve it? what's the answer

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

Find the value of the variable and the length of each secant segment.

Rob spent 25%, percent more time on his research project than he had planned. he spent an extra h hours on the project. which of the following expressions could represent the number of hours rob actually spent on the project? two answers