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secondary 3 | A Maths
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Date Posted: 3 years ago
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We reject two of the k values because a re-substitution back into the original equation will not get us correct results.
This is because if square root k is -1, for example, then k = (-1)^2 = 1, but then if you are asked to calculate the value of the square root of 1, then -1 is actually not a valid answer.
Square root of 1 is strictly 1, and not -1. This is different from solving x^2 = 1, where solving this leads to x = +- sqrt 1, where we put the +- in front to account for the power 2 while the square root itself has a value of 1.
This is because if square root k is -1, for example, then k = (-1)^2 = 1, but then if you are asked to calculate the value of the square root of 1, then -1 is actually not a valid answer.
Square root of 1 is strictly 1, and not -1. This is different from solving x^2 = 1, where solving this leads to x = +- sqrt 1, where we put the +- in front to account for the power 2 while the square root itself has a value of 1.
Date Posted:
3 years ago
Thx alot
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