Basic Mathematics ! :)

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Demio

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May 8, 2015
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if
MSP33661h7g1g2bi46bb5ha00004547h376gd5061b1
= 4

then what is

a^2 + 1/a ?
 
Well, you're given [(a+1)/(a+2)]^2 = 4. Since 4 is a perfect square, I'd take the square root of both sides. Remember that the square of 4 can be either 2 or -2. So you have two new equations: (a+1)/(a+2) = 2 or(a+1)/(a+2) = -2. Can you solve that? Once you do, plug in your values for a into the other equation.

Although, there is an issue I see. In your first post, you said the question was a^2+(1/a) = ?. But in your reply, you say the question is a^2+(1/a^2) = ?. Both would be solved in the same way, but it's important to be clear about what problem you're working so you get the expected answer.
 
Last edited:
thank you !
I got the answer when -2 was taken into consideration ..
 
ksdhart said:
Well, you're given [(a+1)/(a+2)]^2 = 4. Since 4 is a perfect square, I'd take the square root of both sides. Remember that the square of 4 can be either 2 or -2. So you have two new equations: (a+1)/(a+2) = 2 or(a+1)/(a+2) = -2. Can you solve that? Once you do, plug in your values for a into the other equation.

Although, there is an issue I see. In your first post, you said the question was a^2+(1/a) = ?. But in your reply, you say the question is a^2+(1/a^2) = ?. Both would be solved in the same way, but it's important to be clear about what problem you're working so you get the expected answer.
Click to expand...

sorry ! i still don't get the answer ..
the options are
1) 12 , 2) 13 3) 14 4)15
In which they say answer is 14 .
Can you please help me out
 
Demio said:
sorry ! i still don't get the answer ..
the options are
1) 12 , 2) 13 3) 14 4)15
In which they say answer is 14 .
Can you please help me out
Click to expand...

Please show your calculations - so that we can guide you to the correct answer.
 
Demio said:
Oops ! I'm so sorry !

The Problem is ..
If , ( a+1/a +2 ) ^2 = 4
Then
What is a^2+ 1/a^2

I hope you get what I'm trying to tell ...
Click to expand...
First make sure you are posting the problem correctly!

Your post is equivalent to:

If \(\displaystyle (a + \frac{1}{a} + 2)^2\) = 4, then what is \(\displaystyle a^2 + \frac{1}{a^2}\)?

If you meant to write

If \(\displaystyle \left(\frac{a+1}{a+2}\right )^2\) = 4, then what is \(\displaystyle a^2 + \frac{1}{a^2}\)?

, then you should have written:

If , [(a+1)/(a +2)]^2 = 4 Then What is a^2+ 1/a^2 - those parentheses are super important to do the problem correctly!

Then - I doubt the answers given.

Only time x + 1/x becomes a positive integer is when x = 1. That is not possible from the given conditions.
 
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