004 Sample Final A, Problem 15 - Revision history

Kayla Murray at 17:36, 29 April 2015

2015-04-29T17:36:05Z

2015-04-29T17:34:46Z

2015-04-29T17:16:58Z

2015-04-29T17:15:34Z

2015-04-28T22:47:14Z

Created page with "<span class="exam"> Solve. <math>\log(x + 8) + \log(x - 1) = 1</math>"

New page

<span class="exam"> Solve. <math>\log(x + 8) + \log(x - 1) = 1</math>

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 ! Step 4:
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-|We have to make sure the answers make sense in the context of the problem. Since the domain of the log function is <math> (0, \infty)</math>, -9 is removed as a potential answer. The answer is <math>x=2</math>.
+|We have to make sure the answers make sense in the context of the problem. Since the domain of the log function is
 |}

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 |Answer:
 |-
+|1) One of the rules of logarithms states that <math>\log(x)+\log(y)=\log(xy) </math>
 |-
+|2) The definition of the logarithm tells us that if <math>\log(x)=y</math>, then <math>10^y=x</math>.
 |}
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 ! Step 1:
 |-
+|Using a rule of logarithms, the equation becomes <math>\log((x+8)(x-1))=1</math>.
 |}
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 ! Step 2:
 |-
+|By the definition of the logarithm, <math>\log((x+8)(x-1))=1</math>
 |}
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 ! Step 3:
 |-
+|Now, we can solve for <math>x</math>. We have <math>0=(x+8)(x-1)-10=x^2+7x-18=(x+9)(x-2)</math>.
 |}
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 ! Step 4:
 |-
+|We have to make sure the answers make sense in the context of the problem. Since the domain of the log function is <math> (0, \infty)</math>, -9 is removed as a potential answer. The answer is <math>x=2</math>.
 |}
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 ! Final Answer:
 |-
+| <math>x=2</math>
 |}
 [[004 Sample Final A|<u>'''Return to Sample Exam</u>''']]

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 !Foundations
 |-
+|1) How can we combine the two logs?
 |-
+|2) How do we remove logs from an equation?
 |-
 |Answer:

← Older revision		Revision as of 17:15, 29 April 2015
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	<span class="exam"> Solve. <math>\log(x + 8) + \log(x - 1) = 1</math>		<span class="exam"> Solve. <math>\log(x + 8) + \log(x - 1) = 1</math>
		+	{\| class="mw-collapsible mw-collapsed" style = "text-align:left;"
		+	!Foundations
		+	\|-
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		+	\|-
		+	\|Answer:
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		+	\|}
		+
		+	Solution:
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		+	{\| class="mw-collapsible mw-collapsed" style = "text-align:left;"
		+	! Step 1:
		+	\|-
		+	\|
		+	\|}
		+
		+	{\| class="mw-collapsible mw-collapsed" style = "text-align:left;"
		+	! Step 2:
		+	\|-
		+	\|
		+	\|}
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		+	{\| class="mw-collapsible mw-collapsed" style = "text-align:left;"
		+	! Step 3:
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		+	\|
		+	\|}
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		+	{\| class="mw-collapsible mw-collapsed" style = "text-align:left;"
		+	! Step 4:
		+	\|-
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		+	\|}
		+
		+	{\| class="mw-collapsible mw-collapsed" style = "text-align:left;"
		+	! Final Answer:
		+	\|-
		+	\|
		+	\|}
		+
		+	[[004 Sample Final A\|<u>'''Return to Sample Exam</u>''']]