In the following question, five figures are given. Out of them, find the three figures that can be joined to form a square.
When combining multiple pieces:
• Total outer boundary must be a square
• Inner edges should cancel out
A particle is moving in a straight line. The variation of position $ x $ as a function of time $ t $ is given as: $ x = t^3 - 6t^2 + 20t + 15 $. The velocity of the body when its acceleration becomes zero is: