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algebra 2020 summer

 
 
huangDanny的头像
algebra 2020 summer
huangDanny - 2020年08月6日 Thursday 15:45
 

For 7.28, we need to solve the value a  that have the maximum root. In your answer key, how do you know the maximum root is cube root of 2 over 2? You did not make any explanation , so I am confused. Is Okay. Is there anywhere they might have established that fact about the roots?

Thanks! 

 
ShiJames的头像
Re: algebra 2020 summer
ShiJames - 2020年08月7日 Friday 10:43
 

I don't think I'm in the same class as you, but I think I had the same question on my homework. Try rewriting the equation as a quadratic with $a$ as the variable and use the condition that $a$ is a real number.

 
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WangDr. Kevin的头像
Re: algebra 2020 summer
WangDr. Kevin - 2020年08月9日 Sunday 23:40
 

This is for the MC II-A course.

Question 7.28 is referring to question 7.8: 

Let $a$ be a real number, and the equation $x^2+a^2x+a=0$ has real roots for $x$. Find the maximum possible root $x$.

The solution to Question 7.8 is in the lecture video, and also available in the book.  Question 7.28 is an additional question based on that.

To James Shi: Good! This is the same question in MC III.  There are multiple practices with this technique and I hope everyone learns the mathematical ideas behind it.

 
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