Spending an hour on a maths question that makes no sense can be really annoying. I mean it's a quadratic equation that should be solvable by simply factorising, but I'm pretty darn sure there aren't two (whole) numbers that can add to give -4 and multiply to give 12.
Most of the time I've normally written or calculated something incorrectly earlier on but it looks like it's all correct. Most likely it's something that will look painfully obvious tomorrow. Or it's yet ANOTHER typo in the school booklets.
EDIT: Thinking like a coder, I figured I could debug my calculations, since I had a graph that clearly showed the x values I'd end up with (of course the question was asking to prove it algebraically). So with code I always trace the output in each of my steps until it traces something that shouldn't be there, which is where the problem is. Same here: I replaced x with one of the x values on the graph, and once it didn't comply with my equation I knew it was incorrect, and focused on finding a flaw in my equation. I had to do this a few times but eventually I ended up with a solvable quadratic, which also gave me the x values seen on the graph.
I really should try to make less mistakes in my equations though
Most of the time I've normally written or calculated something incorrectly earlier on but it looks like it's all correct. Most likely it's something that will look painfully obvious tomorrow. Or it's yet ANOTHER typo in the school booklets.
EDIT: Thinking like a coder, I figured I could debug my calculations, since I had a graph that clearly showed the x values I'd end up with (of course the question was asking to prove it algebraically). So with code I always trace the output in each of my steps until it traces something that shouldn't be there, which is where the problem is. Same here: I replaced x with one of the x values on the graph, and once it didn't comply with my equation I knew it was incorrect, and focused on finding a flaw in my equation. I had to do this a few times but eventually I ended up with a solvable quadratic, which also gave me the x values seen on the graph.
I really should try to make less mistakes in my equations though