How to implement object movement?

Question

Physics

There is an object that must move in a given direction in 2d, the speed with which this object must move and the angle (the direction of movement is 0-360 degrees) is given. We need to implement movement using a function that takes 2 parameters X and Y.
My course of action:

• 1) decompose the speed into two projection speeds
  Vx=V*cos(alpha); Vy=V*sin(alpha)
  
• 2) find the position of the object at a certain moment
  x=Vx*t*cos(alpha); y=Vy*t*sin(alpha);
  
• 3) I substitute the resulting coordinates into the function (this function is called once every t seconds, so the variable t changes)
  

The problem is that the object is moving in the wrong direction. How so?

Answer 1

x = x0 + V * cos(alpha) *
t

Answer 2

x += V*cos(alpha)*t