1. The problem statement, all variables and given/known data A ball is trown vertically straight up in the air. After t seconds the ball has reached the higth Question : after how many sconds is the ball back to the spot it was trown from ? 2. Relevant equations I have figured out that i need to differentate. 3. The attempt at a solution So i thought i had to solve it this was : 60t – 5t2 --> 60-10t but it seems like this isnt the answer besides i have made a drawing of the information i got . The orange line shows how the ball is thrown straight up, and the blue shows that i have to solve how much that and the orange are when they are added when reffereing to time in seconds .