If A = (x - 1)/(x + 1) , then find the value of A - (1/A).
Show answer & explanation
Correct answer: D
Explanation
The correct answer is Option 4 i.e (-4x)/(x2 - 1).
| Understanding/Application |
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A = (x - 1)/(x + 1) A - 1/A = [(x - 1)/(x + 1)] - 1/[(x - 1)/(x + 1)] |
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A - 1/A = [(x - 1)2 - (x + 1)2]/x2 - 1 = (x2 - 2x + 1 - (x2 + 1 + 2x))/x2 - 1 = -4x/(x2 - 1) |