# Piston displacement

#### Flimjabs

##### New member
Hi everybody
Displacment =25cos(200t+1.3)
I'm stuck on part E which is
Where does the piston sit when t=0
I have attached the making to this thread, can someone check my reworking, I'm assuming I need to convert radians to degrees so
25cos(1.3×57.3)=6.68mm is this the position when t=0 or do I subtract that from 25mm?