I had a problem on the test I just took that I have never seen before.
$x^2 + 2y^2 = 1$ and was suppose to find the tangent lines on that curve that have a slope of one.
I just couldn't figure out how to do it. I am not even sure if I did anything but I got the derivative as
$2x + 4y y\prime$ and then from there I did some algera but I don't think any of that was correct.