Field Guide/Geometry/Multiple trig solutions
Exam essential3 min

Find every trig solution in an interval

A trigonometric equation asks for all solutions in a bounded interval.

01

Press these keys

Y=GRAPH2ndTRACE5:intersect

Step 1 of 5. Press Y=.

02

Walkthrough

  1. 1
    Graph both sides

    Enter the left and right sides in Y1 and Y2.

  2. 2
    Use the full interval

    Set Xmin and Xmax exactly to the required interval and a useful y-window.

  3. 3
    Repeat intersection

    Find each crossing separately, moving the cursor near the intended one.

03

Worked example

Solve sin x=0.4 for 0≤x≤2π.

Answerx≈0.412 or 2.730 radians.