This is a fun mistake, via Jonathan Newman. Find it, and then explain how you’d help the kid who made it.

  • sin^2(t) != cos^2(t) - 1, it should be sin^2(t) = 1 - cos^2(t). I think this is just a simple algebra mistake, or just going too quickly and not thinking through the subtraction properly.

  • Oh, looks like Latex in comments isn’t enabled.

  • Oh Isn’t Michael nice to fix our Latex? Let me give it a go ( my Sunday efforts!)
    cos ^{2}t-( 1-cos ^{2}t) ) which is 2( cos ^{2}t) -1 or you can use the trig identity cos 2t if you remember it.

  • Okay, Michael, punting to you. Again. It worked for cos 2t. the parentheses are wrong.
    cos^(2)t -sin^(2)t which is 2(cos^(2)t -1 or you can use the trig identity cos2t if you remember it.