lnx^2=9 the answer is supposd to be -e^9/2 and e^9/2
how did they get the answer to be both positive and negative? and how did they even get that answer? step by step please:]
logarithm and square rooting?
2009-05-03 10:07 am
回答 (7)
2009-05-03 10:32 am
✔ 最佳答案
you seem to have got the answering procedure from many others . I'll just explain why you are getting both the signs . the reason is that Sq rt(x^2) is given by Modulus of x ( mod(x) ) . Thats why you're getting both postive and negative answers due to the modulus as
mod(2) = 2 = mod(-2) . hope you got it.
2016-12-11 8:53 am
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2009-05-03 10:20 am
Re-write the expression using the exponential form :
e^9 = x²
So x = ±√(e^9) = ± (e^9/2)
(√n is equivalent to n^½ )
e^9 = x²
So x = ±√(e^9) = ± (e^9/2)
(√n is equivalent to n^½ )
2009-05-03 10:19 am
First, note that "ln" is logarithm in base "e". So, using the properties of logarithms that: (2)log(x) = 3 equals to 2^3=x, we have:
ln(x^2) = 9
e^9 = x^2
As the solution for x^2 = 4 is +sqrt(4) and -sqrt(4), we also get for this case, the value of x is:
x = +sqrt(e^9) = +e^(9/2)
or
x = -sqrt(e^9) = -e^(9/2)
Hope that helps.
ln(x^2) = 9
e^9 = x^2
As the solution for x^2 = 4 is +sqrt(4) and -sqrt(4), we also get for this case, the value of x is:
x = +sqrt(e^9) = +e^(9/2)
or
x = -sqrt(e^9) = -e^(9/2)
Hope that helps.
2009-05-03 10:18 am
e^(lnx^2) = e^9
x^2 = e^9
x = (e^9)^(1/2) or - (e^9)^(1/2)
x^2 = e^9
x = (e^9)^(1/2) or - (e^9)^(1/2)
2009-05-03 10:17 am
ln(x^2) = 9
x^2 = e^9
x = ±√(e^9)
x = ±√[(e^4)^2 * e]
x = ±e^4√e
x^2 = e^9
x = ±√(e^9)
x = ±√[(e^4)^2 * e]
x = ±e^4√e
2009-05-03 10:16 am
ln(x^2) = 9
x^2 = e^9
x = +/- sqrt(e^9) = +/- e^(9/2)
x^2 = e^9
x = +/- sqrt(e^9) = +/- e^(9/2)
收錄日期: 2021-05-01 12:26:17
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