Sharp EL-9600 - Page 17

For Discussion
Students can use the calculators to discuss how "toggling" (using the ▲ and
▼ keys while tracing) between Y1 and Y2 verifies the same values for both Y1
and Y2, and they can explore what happens when they do not limit the domain
on those problems with ± parts (they see two graphs).
Additional Problems
Verify the following formulas and identities graphically.
1. cos 2θ = cos
2
θ – sin
2
θ
2. 1 + cot
2
θ = csc
2
θ
3. sin
2
θ cot
2
θ = (1 + sin θ)(1 – sin θ)
Graphical Verification of Formulas and Identities/TRIGONOMETRY USING THE SHARP EL-9600 13