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Algebra Level 1

( 7 + 4 3 2 + 3 ) 2016 = ? \large \left (\frac{\sqrt{7 + 4\sqrt{3}}}{2 + \sqrt{3}} \right)^{2016} = \, \ ?


The answer is 1.

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5 solutions

Milan Milanic
Jan 12, 2016

Solution:

On the numerator we will use this formula:

I don't know the name of that identity in English, so if anyone knows, please, write a reply or something, that would mean a lot for me. I am learning mathematical terms.

One of the condition for using the identity is a b a \ge \sqrt{b} , and that is fulfilled since 49 > 48 49 > 48 . After that we will get that the numerator is as same as the denominator, therefore the fraction is 1 1 .

You are fool

Arun Garg - 5 years, 2 months ago
Jack Cornish
Jan 12, 2016

We desire to write 7 + 4 3 7+4\sqrt{3} as a perfect square. This is done by saying ( a + b 3 ) 2 = 7 + 4 3 (a+b\sqrt{3})^2 = 7+4\sqrt{3} . We then have a 2 + 3 b 2 = 7 a^2+3b^2 = 7 and a b = 2 ab =2 . We can guess and check the solution a = 2 , b = 1 a = 2, b = 1 . Then we see that 7 + 4 3 = 2 + 3 \sqrt{7+4\sqrt{3}} = 2+\sqrt{3} and ( 7 + 4 3 2 + 3 ) 2016 = 1 \left(\dfrac{\sqrt{7+4\sqrt{3}}}{2+\sqrt{3}}\right)^{2016} = 1 .

Nice solution. As you can see, I used some identity, whose name I don't even know. It seems that was unnecessary. Good work!

Milan Milanic - 5 years, 5 months ago
Zyberg Nee
Feb 13, 2016

Simply read the title of the problem and look at the equation with the power of 2016 2016 . The only possible way (that wouldn't take ages) to count it would be if the fraction inside was equal to either 1 1 or 0 0 or 1 -1 and either way the answer would be 1. ;)

This is not a solution. You just guessed the correct answer, and didn't give a solution to the problem.

Jesse Nieminen - 3 years ago
Jesse Nieminen
Jun 13, 2018

Notice that, 2 + 3 = 2 + 3 = ( 2 + 3 ) 2 = 2 2 + 2 × 2 3 + 3 2 = 7 + 4 3 2 + \sqrt{ 3 } = \left| 2 + \sqrt{ 3 } \right| = \sqrt{ \left( 2 + \sqrt{ 3 } \right)^2 } = \sqrt{ 2^2 + 2 \times 2 \cdot \sqrt{ 3 } + \sqrt{ 3 }^2 } = \sqrt{ 7 + 4 \sqrt{ 3 } }

Hence the expression simplifies to 1 \boxed{1}

Sagar Shah
Jan 17, 2016

7 + 4 3 7+4\sqrt{3} can be written as 4 + 3 + 2 × 2 3 4+3+2×2\sqrt{3} .

ie. 2 2 + ( 3 ) 2 + 2 × 2 3 2^2+{(\sqrt{3})}^2+2×2\sqrt{3}

or ( 2 + 3 ) 2 {(2+\sqrt{3})}^{2}

Thus our problem reduces to ( 2 + 3 ) 2 2 + 3 2016 {\dfrac{\sqrt{{(2+\sqrt{3})}^2}}{2+\sqrt{3}}}^{2016}

Which is equal to 1 2016 1^{2016} ie. 1 1 .

Hence our answer is 1 1 .

@Jack Cornish can you please edit my solution to make it visible clearly..I don't know how to write in latex..

Sagar Shah - 5 years, 4 months ago

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It won't let me edit yours, but I put the code below and just put the slash brackets around the math expressions to get the latex.

7+4\sqrt{3} can be written as 4+3+2*2\sqrt{3}.

ie. 2^2+(\sqrt{3})^2+2*2\sqrt{3}

or (2+\sqrt{3})^{2}).

Thus our problem reduces to \dfrac{(\sqrt{(2+\sqrt{3})^2)}}{2+\sqrt{3}}^{2016}

Which is equal to 1^{2016} ie. 1.

Hence our answer is 1.

Jack Cornish - 5 years, 4 months ago

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Bro not working..I edited my solution as you did but still solution is not visible..

Sagar Shah - 5 years, 4 months ago

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@Sagar Shah Sagar, put this in...


7 + 4 3 7+4\sqrt{3} can be written as 4 + 3 + 2 × 2 3 4+3+2×2\sqrt{3} .

ie. 2 2 + ( 3 ) 2 + 2 × 2 3 2^2+{(\sqrt{3})}^2+2×2\sqrt{3}

or ( 2 + 3 ) 2 {(2+\sqrt{3})}^{2}

Thus our problem reduces to ( 2 + 3 ) 2 2 + 3 2016 {\dfrac{\sqrt{{(2+\sqrt{3})}^2}}{2+\sqrt{3}}}^{2016}

Which is equal to 1 2016 1^{2016} ie. 1 1 .

Hence our answer is 1 1 .


Now, go to the top right corner of your screen. There you can see a hamburger option which you can use for editing this question. In the dropbox which would appear soon click "Toggle LaTeX". Then scroll this comment of mine and you would see the LaTeX codes i used. Copy the whole thing and put it in your solution. THEN, erase the words Latex: You would see the word Latex and a semicolon : in my solution after putting it in your solution delete them. Then publish it! And let me know :).

Ashish Menon - 5 years, 1 month ago

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@Ashish Menon Thanks..I edited my solution..I will learn LATEX Codes soon..

Sagar Shah - 5 years, 1 month ago

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@Sagar Shah Looks nice now :)

Ashish Menon - 5 years, 1 month ago

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@Ashish Menon All because of you..:)

Sagar Shah - 5 years, 1 month ago

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@Sagar Shah Thanks! Hope you learn LaTeX code soon. You can post a note "Sagar's LaTeX playgroumd" to improbe at LaTeX by practosong LaTeX \LaTeX there ;)

Ashish Menon - 5 years, 1 month ago

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