4 ms·
That is unbelievably terrible. You would lose points for a mathematically sound justification?!?! For example, when solving quadratic equations, I often used t
by sanxiyn 12y ago
That is unbelievably terrible. You would lose points for a mathematically sound justification?!?!
For example, when solving quadratic equations, I often used trial substitutions and the fact quadratic equations have at most two solutions to justify answers, instead of using quadratic formula. Why wouldn't this get the full mark? (I would actually argue this is a better procedure if you are looking for integer-only solutions, for example.)
- fredophile 12y agoWhat do you mean by "trial solutions"? Were you just substituting numbers for x and seeing if they worked out? If that is what you mean I can't see why it would be a better procedure than using the quadratic formula.
- sanxiyn 12y agoYes, I meant substituting numbers for x and seeing if they worked out. To get integer solutions, it's enough to try divisors of the constant term. Try it yourself. It's faster.
- fredophile 12y agoYes, it is faster for small integer values. Most numbers aren't small integer values. Test questions are usually designed to give nice clean answers but the real world isn't like that. They were trying to test your ability to solve quadratic equations in the general case. Your approach doesn't demonstrate that ability.