Set degrees or radians before you graph sine or cosine. Then type the function and read amplitude, intercepts, or a value off the curve. Wrong mode is the expensive miss. The switch is in radians versus degrees.
What the graph gives you
Amplitude is the height from the midline. Period is the x-distance before the wave repeats. A question that asks for sin(30°) is faster as a keypad evaluation than as a graph, in evaluating a function at a point.
SOH-CAH-TOA on a right triangle does not need a wave at all, in SOH-CAH-TOA. Desmos availability is in Desmos on the ACT.
The bottom line
Wrench first, then graph. Use the curve for shape. Use the keypad for a single trig value.
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.