Calculate two more times to find the third and fourth solutions.
Note that 2.3562 radians is an integral multiple of - .7854 radians. Therefore,
there are three solutions - .7854, .5236, and 2.618.
For Discussion
Students can use the calculators to verify the additional solutions at integral
multiples of the function's period.
Additional Problems
Solve the following equations using either the zoom or CALC feature:
2
1. 2cos
x – 5cos x + 2 = 0 (in degrees)
2
2. tan
x = cot x (in degrees)
2
3. 2cos
x = sin x + 1 (in degrees)
2
4. 3tan
x + 4sec x + 4 = 0 (in radians)
5. cos x tan x – sin
6. 2sin x cos x + 4sin x = cos x + 2 (in radians)
28
Solving Trigonometric Equations/TRIGONOMETRY USING THE SHARP EL-9600
2
x = 0 (in radians)