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I need help understanding how to find the exact value of y. I see in the back of book the answer is 9, but don't understand *how* this is calculated.

2007-05-27 14:33:53 · 6 answers · asked by RogerDodger 1 in Science & Mathematics Mathematics

6 answers

Solve for y.

y = e^[2*ln(3)] = e^[ln(3²)] = 3² = 9

2007-05-27 14:38:21 · answer #1 · answered by Northstar 7 · 1 0

Use the property of logs to write 2*ln(3) = ln(3^2) = ln(9)
(the coefficient becomes the exponent )
Then use the fact that ln x and e^x are inverse functions:
e^(2*ln(3)) = e^(ln(3^2)) = e^(ln(9)) = 9

2007-05-27 21:40:46 · answer #2 · answered by Math Nerd 3 · 0 0

Rewrite it as

y = (e^ln(3))^2
(this uses the rule of exponents: b^cd = (b^c)^d)

But e^ln(a) = a for any a, so

this just becomes

y = 3^2 = 9

2007-05-27 21:39:50 · answer #3 · answered by Eve D 3 · 0 0

step 1, replace 2*ln(3) to ln(3)^2 (power property):
y = e^(ln(3)^2)

step 2, replace e^(ln(3)^2) to 3^2 because e^ln = 1:
y = 3^2

step 3, solve:
y = 9

2007-05-27 21:40:59 · answer #4 · answered by wormhole 3 · 1 0

Scientific calculator :

1) 3
2) ln
3) x
4) 2
5) =
6) eˣ

2007-05-27 22:49:22 · answer #5 · answered by Zax 3 · 0 0

y = e^(2*ln(3)) = e^(ln(3^2))=e^(ln(9))=9

2007-05-27 21:49:35 · answer #6 · answered by qwert 5 · 0 0

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