How would you solve this in order to find t?
0.2t(t-5.1)(t-9.1)=2.4+0.75t
I tried differentiating it, but I wasn't getting the answer I was supposed to
why take the derivative to find t? It won't help here. Just expand and solve:
0.2t^3 - 2.84t^2 + 9.282t = 2.4 + 0.75t
0.2t^3 - 2.84t^2 + 8.532t - 2.4 = 0
Now you can fall back on graphical methods, or Newton's method or something you have in your bag of tricks.