Quadratic Formula - TI 85

Introduction
This program solves equations of the form Ax2+Bx+C=0 by using the quadratic formula.
 
If you have not used one of the programs posted on this website before, you should read through the information in the Intro to Programming section first.


The Program
:Prompt A,B,C {Prompt is in PRGM under I/O}
:(B2-4*A*C)D {The arrow is STO}
:If D<0 {If is in PRGM under CTL} {< is in TEST }
:Then {Then is in PRGM under CTL}
:Disp "NO REAL SOLUTIONS" {Disp and " are in PRGM under I/O} {Words within "" are typed using ALPHA}
:Goto P {Goto is in PRGM under CTL}
:Else {Else is in PRGM under CTL}
:((-B+(D))/(2A))E {The is square root}{The - is the negative sign}
:((-B-(D))/(2A))F {The second - is the subtraction sign}
:Disp "SOLUTIONS",E,F
:Lbl P {Lbl is in PRGM under CTL}


Running the program
 
You will be asked to enter values for A, B, and C according to the quadratic formula. To test your program try the following:
 
A=2, B=3, C=4. Your answer should be NO REAL SOLUTIONS.
 
A=5, B=4, C=-2. Your answer should be .348331477355, -1.14833147735.