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प्रश्न
Evaluate the following using identities:
`(2x+ 1/x)^2`
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उत्तर
In the given problem, we have to evaluate expressions by using identities.
Given `[2x - 1/x]^2`
We shall use the identity `(a - b)^2 = a^2 - 2ab + b^2`
Here a = 2x
`b = 1/x`
By applying identity we get
`[2x - 1/x]^2 = (2x)^2 + (1/x)^2 - 2 xx 2 xx x xx 1/x`
`= (2x xx 2x) + (1/x xx 1/x) - 2 xx 2 xx x xx 1/x`
` = 4x^2 + 1/x^2 - 4`
Hence the value of `[2x - 1/x]^2 is [4x^2 + 1/x^2 - 4]`
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