Question: how to do nsolve on ti-84?
Answer: Press [MATH][0] to access the Equation Solver from the Math menu. ... 
If your Equation Solver already contains an equation, repeatedly press. ... 
If you need to, press [CLEAR] to erase any equation in the Solver and enter the equation you want to solve. ... 
Press [ENTER] to enter the equation in the solver.