You can use your GDC to find numerical solutions to equations.
Open a calculator page.

• Press menu > "3: Algebra" > "1: Numerical Solve"
• In the brackets, type $x^2-x-2=0,x$ then press enter
What was the result? Check

By default, the GDC will find the solution closest to zero. To restrict the domain, use "|"

• Press ▴ until you highlight $nSolve(x^2-x-2=0,x)$, then press enter
• Press ctrl = then choose "|"
• Type $x$ ctrl =, choose "≥", then type $0$ and press enter
What was the result? Check