Set the axis ranges so the useful part of the graph is on screen. Zooming out blindly is slower than typing the window. This is axis limits, not pinch-zoom. Off-screen graphs as a habit are in zooming a missing graph.
Type the bounds
If x should run from 0 to 50, set that. If a vertex is at (20, −80), the default window will hide it. Finding that vertex is in finding a vertex.
Both x and y showing is a cue to graph, in if you see x and y. Desmos access is in Desmos on the ACT.
The bottom line
Choose the window from the numbers in the problem. Do not hunt on the default square.
Start practicing
Start with a free diagnostic, then drill your weak spots with 15-question quizzes and track how you're doing across Reading, English, and Math. Compare plans whenever you're ready to go further.
This article offers general ACT prep guidance. The ACT can change from year to year, including its format, scoring, policies, test dates, and fees, so always confirm the latest details on the official ACT website at act.org before you make decisions. ACT® is a registered trademark of ACT, Inc. thirty-six is not affiliated with, endorsed by, or sponsored by ACT.