Online Course Discussion Forum

MCIV Spring Inequalities - Part 3 Example 8

 
 
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MCIV Spring Inequalities - Part 3 Example 8
by DL Yu - Monday, March 30, 2020, 8:58 AM
 

In Example 8, the question was

(ZIML Varsity January 2019) Let $x$ be a real number, find the maximum value of

$$\sqrt{4x-3} + \sqrt{2-x},$$

rounded to the nearest tenth if necessary.

The solution given in the video was to decompose $\sqrt{4x-3}$ into 4 parts, but instead couldn't you have just factored out the 4 to get $2\sqrt{x-\frac{3}{4}}$ and done Cauchy with $a_1 = 2,a_2=1,b_1 = \sqrt{x-\frac{3}{4}},b_2 = \sqrt{2-x}$? I think this works but I want to confirm that it does. I got the same answer in the video doing this. 

 
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Re: MCIV Spring Inequalities - Part 3 Example 8
by Dr. Kevin Wang - Tuesday, March 31, 2020, 12:10 PM
 

Yes, it works; result is the same.