Incorrect Caclulation of Inverse Cosine

[theoriginalmattcook]

Describe the bug
The calulator produces an incorrect result for the inverse cosine of -.28 in degrees

Steps To Reproduce

1. -.28
2. 2nd - Inverse Cosine
3. Enter

Expected behavior
=106.2602047

Screenshots

[686f6c61]

Hi, @theoriginalmattcook . Not a bug - just a case of "GRAD" vs "DEG" confusion!

I looked into this and your calculator is working perfectly. The "bug" is actually hiding in plain sight in the top-left corner of your screenshot: GRAD mode is enabled.

Your calculator is speaking in gradians (the French Revolutionary unit because apparently degrees were too mainstream),
while Desmos is speaking in good old degrees.

Quick math check:

- 106.2602047° × (400/360) = 118.0668941 gradians

Mystery solved!

Just click on "GRAD" until it shows "DEG" and you'll get the expected result.

TL;DR: Your calculator isn't wrong, it's just being extra European about angles.

[onu032001]

$106.26020 \degree = 118.06689\ \text{gradians}$. Click on the GRAD sign until you see DEG.