What is the value?
Find the value of 1 + 2 1 + 2 + 3 1 + 3 + 4 1 + 4 + 5 1 + 5 + 6 1 + 6 + 7 1 + 7 + 8 1 + 8 + 9 1
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The answer is 2.
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5 solutions
Wouldn't you get the square root of 2 minus 1 if you plugged in 1 for k?
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after that if u put 2 in place of k, root of minus 2 and root of 2 will cancel out...and same will happen for other terms also..
I always had problem in this type of questions....thanks a lot.... :)
But how did you just plug 8 & 1 into the formula?
Think this as writing denominator in terms of denominator. So express 1=2-1 , 1 =3-2 and so on .then 2-1=(√2-√1)(√2+√1) ... and so on .
Rationalize the denominator of all terms...after that we will have 1-2 , 2-3 so on as denominator which is -d by (negative common diffence)..take 1/-d common...then we will have (1-9^1/2) * 1/-d...
rationalize the denominators !!!!! and you have your answer!
The exact answer is not an integer it's 1.95
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Why do you say that?
rationalise each term ,thereby getting 1in the denominator for each and we will be left out with square root of 9 minus 1= 3-1=2
rationalize the factor by multiplying the denominator by (root 2 -1),(root 3 - root 2) and so on...all other terms will cancel out except (-1) and root 9..hence -1+3=2..thts the ansr..
Rationalizing, each term can be expressed as k + k + 1 1 × k + 1 − k k + 1 − k = k + 1 − k and then the sum can be written as k = 1 ∑ 8 ( k + 1 − k ) = 9 − 1 = 3 − 1 = 2