MATLAB用来plot二次函数的问题.我不晓得这个题要回答哪个方面Plotthefunctiony=a*x.^2+b*x+cusingx=[-10..10].Tryenteringa=1,b=3,c=-10.Rememberwhatyousee.Entera=1,b=30,c=-1000.Whatdoyouseenow

Question

MATLAB用来plot 二次函数的问题.我不晓得这个题要回答哪个方面
Plot the function y = a*x.^2 + b*x + c using x = [-10..10].
Try entering a = 1, b = 3, c = -10. Remember what you see.
Enter a = 1, b = 30, c = -1000. What do you see now? Compare with your previous observation!
Then, what happens if we use these values: a = 1, b = -40, c = 400?
Finally, what happens if we use these values: a = 1, b = 0, c = 1?
What is your conclusion with these observations?
Although you can explain this phenomenon mathematically, your task here is to utilize debugging
feature shown above to identify what is/are the `error(s)'?
Suggest some improvements to the code to address the issues that you found in above question

Answer 1

第一个问题:
联立方程后有两种情况,有实解,无实解,如果无实解则说明无法在实解范围内同时满足两等式成立,而虚解,也即是带有i的解在3x+4y是无大小之分的,也就没有最大最小值,所以必须是实解,也就有了△≥0然后确定范围
第二个问题:
p是定数的意思是它是一个确定不变的数,可能是2,可能是3,但是我们不知道,如果它是2就不会是3,它不像x可以取很多不同值.此题的意思是先将p看成定值,有解的条件可以确定一个关于P的不等式,那么P的可能值范围给出,然后用P的范围来推出X的解的范围