I made a program I find pretty helpful during math. It includes mostly Algebra, and some Geometry. It was originally made just for my use, so it isn't that user friendly, but I'll give instructions.

```
Lbl P3
ClrHome
Disp "prgmPYTH"
Repeat A=105 or A=21 or A=22 or A=61 or A=45 or A=53
getKey→A
End
If A=105
Then
Goto 1
End
If A=21
Then
Goto 2
End
If A=45
Then
Goto 3
End
If A=22
Then
Goto 4
End
If A=53
Then
Goto F
End
If A=61
Then
Lbl 20
ClrHome
Disp "X² FORMULA"
Prompt A
Prompt B
Prompt C
Repeat θ=45 or θ=105
getKey→θ
End
If θ=45
Then
Goto 20
End
If (B²-4AC)<0
Then
Disp "NO SOLUTION"
Stop
End
((B+√(B²-4AC))/(2A))→D
((B-√(B²-4AC))/(2A))→E
If (B²-4AC)=0
Then
Disp D
Stop
End
Disp D
Disp E
Stop
End
Lbl 1
ClrHome
Disp "A²+B²=C²"
Prompt A
Prompt B
Repeat θ=45 or θ=105
getKey→θ
End
If θ=45
Then
Goto 1
End
(A²+B²)→C
√(C
Disp Ans
Stop
Lbl 2
ClrHome
Disp "SIN, COS, TAN"
Repeat A≠0
getKey→A
End
If A=52
Then
Goto 2A
End
If A=53
Then
Goto 2B
End
If A=54
Then
Goto 2C
End
Lbl 2A
Repeat X>0
ClrHome
Disp "sin(X)=OPP/HYP"
Prompt X
End
Prompt Y
Prompt Z
If X>0 and Y>0 and Z>0
Then
Goto 2A
End
Repeat θ=105 or θ=45
getKey→θ
End
If θ=45
Then
Goto 2A
End
If Y=0
Then
Z*sin(X)
Disp Ans
Stop
End
If Z=0
Then
Y/sin(X)
Disp Ans
Stop
End
Lbl 2B
Repeat X>0
ClrHome
Disp "cos(X)=ADJ/HYP"
Prompt X
End
Prompt Y
Prompt Z
If X>0 and Y>0 and Z>0
Then
Goto 2B
Repeat θ=105 or θ=45
getKey→θ
End
If θ=45
Then
Goto 2B
End
If Y=0
Then
Z*cos(X)
Disp Ans
Stop
End
If Z=0
Then
Y/cos(X)
Disp Ans
Stop
End
Lbl 2C
Repeat X>0
ClrHome
Disp "tan(X)=OPP/ADJ"
Prompt X
End
Prompt Y
Prompt Z
If X>0 and Y>0 and Z>0
Then
Goto 2C
End
Repeat θ=105 or θ=45
getKey→θ
End
If θ=45
Then
Goto 2C
End
If Y=0
Then
Z*tan(X)
Disp Ans
Stop
End
If Z=0
Then
Y/tan(X)
Disp Ans
Stop
End
Lbl 3
ClrHome
Disp "S1, S2, S3"
Prompt A
Prompt B
Prompt C
Repeat θ=105 or θ=45
getKey→θ
End
If θ=45
Then
Goto 3
End
If A=0
Then
(B+C)→D
(max(B,C)-min(B,C))→E
Disp E
Disp "<X<"
Disp D
End
If B=0
Then
(A+C)→D
(max(A,C)-min(A,C))→E
Disp E
Disp "<X<"
Disp D
End
If C=0
Then
(A+B)→D
(max(A,B)-min(A,B))→E
Disp E
Disp "<X<"
Disp D
End
If A>0 and B>0 and C>0
Then
(A+B>C)→D
(A+C>B)→E
(C+B>A)→F
min({D,E,F})→D
End
If D=1
Then
Disp "TRUE"
Else
Disp "FALSE"
End
If (A≤0 and B≤0) or (B≤0 and C≤0) or (A≤0 and C≤0) or (A≤0 and B≤0 and C≤0)
Then
Goto 3
End
Stop
Lbl 4
ClrHome
Input "SIDES: ",A
If A=0
Then
Goto 4B
End
((A-2)*180)/A
Disp "INTERIOR ANGLE"
Disp Ans
180-Ans
Disp "EXTERIOR ANGLE"
Disp Ans
Stop
Lbl 4B
Input "EXTERIOR ANGLE: ",B
If B=0
Then
Goto 4C
End
360/B
Disp "SIDES"
Disp Ans
Stop
Lbl 4C
Input "INTERIOR ANGLE: ",C
(180-C)→B
360/B
Disp "SIDES"
Disp Ans
Stop
Lbl F
Repeat A=75
getKey→A
End
Repeat A=52
getKey→A
End
Repeat A=41
getKey→A
End
Repeat A=63
getKey→A
End
Repeat A=81
getKey→A
End
Repeat A=105
getKey→A
End
ClrDraw
AxesOff
FnOff
Text(0,0,"FREAKS: TIMMY TRUMPET"
Line(10,8,10,8
Pause
ClrDraw
FnOn
AxesOn
Goto P3
```

You'll also notice that if you hit "cos(" (which happens to be the F key when using ALPHA), none of the buttons work. That's because if you spell out "FREAKS" and hit enter, you'll get the lyrics to Freaks by Timmy Trumpet. I never finished it, so if you want to, go ahead. I'm currently working on adding another Geometry thing, so I'll update this when I finish it, and probably add the lyrics when I get there.

While not very optimized or very big, it is helpful. Here's how it works:

2nd: Gives you the option to choose from Sine, Cosine or Tangent. Click either three buttons, and you'll prompted from there

Clear: This asks you for the sides of a triangle (S1, S2, S3). It will tell you if those sides are possible, or if you leave one as zero, it will tell you the possible solutions. This one doesn't work very well, and the answers don't come out neatly, but I didn't want to add the Number to String formula to save space. I would suggest fixing this if you plan on using this.

X²: Quadratic Formula. If it gives you one answer, it's the only answer.

Enter: Pythagorean Theorem. If you press minus after you hit enter once, it gives you the option to find a side if you already know the hypotenuse. If you want the normal, just press Enter again.

Mode: Asks for an amount of sides, and will give the size of the interior and exterior angles. Use zero if you want to find the interior angles and the amount of sides, or zero again for the exterior angle and amount of sides.

**WIP**

Stats: Yeah, I get that there's already stats, but this does the Mean Aboslute Deviation as well, and is nice enough to tell you the mean and variation as well.

Finish "Freaks" lyrics

It takes up somewhere around 1500 bytes, so nothing too big.

For some things that need a variable (i.e. sine) use 0. If unclear, just ask. As a final note, for some (not all) after you hit enter to confirm the prompts, it will wait for another keypress. Press clear if you entered the wrong number on accident, and need to restart, or enter to reconfirm.

Hope you'll enjoy it. If anyone wants me to make a more user-friendly version, I'd be happy to do so (all you really need is a menu command)

Have a good day 👍