Texas Instruments TITANIUM TI-89 - Manual (Page 748)

Activities 748
Exploring cos(x) = sin(x) Exploring cos(x) = sin(x) Exploring cos(x) = sin(x) Exploring cos(x) = sin(x)
This activity uses two methods to find where cos(x) = sin(x) for the values of x between 0
and 3p.
Method 1: Graph Plot Method 1: Graph Plot Method 1: Graph Plot Method 1: Graph Plot
Perform the following steps to observe where the graphs of the functions y1(x)=cos(x)
and y2(x)=sin(x) intersect.
4. Solve for the value of x that will cause the
inverse of the matrix to be invalid.
Enter:
solve(getDenom(
2 ±
[1,4] )=0,x)
Result: x= L 70/17
Note: Use the cursor in the history area to
scroll the result.
1. In the Y= Editor , set y1(x)=cos(x) and
y2(x)=sin(x) .
2. In the Window Editor , set xmin=0 and
xmax=3 p.
3. Press „ and select
A:ZoomFit .