Yo guys i need help asap

you forgot the picture xD

Step-by-step explanation:

lol its alright i do the same all the time

If you wanna create something with the shape of a rollercoaster you've got to use equations with sinus and cosinus, since their shape varies from K to -K throughout time.

You should use something with this shape:
y = K·sin (x+n)
y = K·cos (x+n)

Sample equations would be:
y = 2·sin (x+1)
y = 5·sin 2x
y = cos (x-3)