There are the following scenarios for each answer (please take your seats accordingly):
"I can do this problem, but I didn't see it clearly!"
"Hey, the formula is wrong!"
"This condition in the title is useless?"
"I'm dizzy! I have reviewed this question before, and I am wrong this time! "
Have you ever sat on it? In view of into the pit's children's boots, which are "conscious" in every exam, let's talk about the reasons why mathematics in senior three is easy to make mistakes and "solving the Dafa".
An error-prone one, the proportion is reversed.
Almost every year, quite a few students lie down with guns. This kind of problem generally appears in the case of choice, and many of them are related to geometry. For example, the ratio of AD to BD is obviously 3 1, but many students fill in 1 3 when choosing.
Reason one: being misled by the "schematic diagram"
When this kind of error occurs, the general topic will give a "schematic diagram". We must remember that the schematic diagram only plays a "schematic" role, and the proportional relationship of line segment length is generally inaccurate. If you judge whether your choice is correct according to the schematic diagram given by the topic, similar mistakes will often occur. Of course, it is also possible that students can't do it, just look at the picture.
Crack Dafa:
When doing this kind of problem, students are advised to draw on paper again. In this case, the proportional relationship of the image is generally more accurate. Even if it is "cute", after drawing an accurate image, the correct probability will greatly increase.
Reason 2: The formula is wrong.
This kind of mistake requires us to strengthen our memory of some formulas, such as the formula of the bisector of the triangle (in the triangle ABC, if the intersection BC of the bisector of ∠ A is at point D, there is AB/ AC= BD/ CD). The order of proportions cannot be reversed. Mistakes caused by remembering wrong formulas must be avoided.
Error-prone second, ignore the hidden conditions of the topic
This kind of mistake usually appears in big questions, such as the existence of absolute value, root number, fraction, inequality, etc., and often implies some implicit conditions such as "greater than or equal to 0" and "the denominator of the fraction is not zero". When we decide the algebraic or functional expression of a topic, we must not forget to use these hidden conditions.
Crack Dafa:
This requires us to keep a certain habit of doing problems. Don't pay too much attention to the "problem" at the beginning, but scan the known conditions of the topic first, and then list these hidden conditions first to simplify the complex.
Then determine whether the objects of these conditions are domain-related conditions of "problems" or scope-related conditions of "problems".
Finally, start the process of solving normal problems (it is suggested to leave a little blank between the above calculated results in the process of solving problems to facilitate later search, and never mark them in the above calculation process). After completing the problem-solving process, intersect with the results calculated by the previous "hidden conditions", and then deduce the conclusion required by the topic.
Although there are ways to correct these common mistakes, it is still necessary for students to pay more attention and concentrate on answering questions to avoid "small mistakes" becoming "big mistakes".