Vividemix3 1,697 Posted October 30, 2014 Share Posted October 30, 2014 Okay I've been stuck on this problem for like the longest time now and I really need help with it. The problem: Use a graphing utility to solve ln(x+3)^2+3x=8 A) Number and describe each step taken. B) What is the solution? (Round to three decimal places) I've tried solving it for x but I just couldn't do it. SO PLEASE HELP ME WITH THIS T____T. IT'S DUE TOMORROW. Link to comment Share on other sites More sharing options...
jvng 3,864 Posted October 30, 2014 Share Posted October 30, 2014 holy fk that looks hard Link to comment Share on other sites More sharing options...
Silktiger 3,227 Posted October 30, 2014 Share Posted October 30, 2014 I'm not sure if this works but you can input y1= ln(X+3)^2+3x y2=8 and then find the intersection and the x-value should be the answer? Link to comment Share on other sites More sharing options...
abra 40,910 Posted October 30, 2014 Share Posted October 30, 2014 Graphic utility? As in... a table? Nvm, it said graphing I wish I could help you but I've never used one of those Link to comment Share on other sites More sharing options...
Jck122 602 Posted October 30, 2014 Share Posted October 30, 2014 Iirc isn't there a ln function on the calculator? Link to comment Share on other sites More sharing options...
mgl 5,919 Posted October 30, 2014 Share Posted October 30, 2014 http://www.wolframalpha.com/input/?i=+ln%28x%2B3%29%5E2%2B3x%3D8 ? Link to comment Share on other sites More sharing options...
guzilla 93 Posted October 30, 2014 Share Posted October 30, 2014 lol people sure are dumb around here @mgl wins Link to comment Share on other sites More sharing options...
Miyami 642 Posted October 30, 2014 Share Posted October 30, 2014 http://www.wolframalpha.com/input/?i=+ln%28x%2B3%29%5E2%2B3x%3D8 ? Wow that is awesome Link to comment Share on other sites More sharing options...
Athena 21,718 Posted October 30, 2014 Share Posted October 30, 2014 Do exactly what silktiger said. Input: y1= ln(X+3)^2+3x y2=8 2. Go to 'Window' and set your X-min as -5, X-max as 5. Y-min as -0, Y-max as 10. Scales at 1. 3. Click 'Graph'. 4. Then Click 2nd --> 'Trace'. 5. Select 'Intersect'. Press 'Enter' button twice. You should find it. x = 1.228 or -1.473 lol people sure are dumb around here @mgl wins That's incorrect though. Link to comment Share on other sites More sharing options...
pygmalion_effect 776 Posted October 30, 2014 Share Posted October 30, 2014 http://www.wolframalpha.com/input/?i=+ln%28x%2B3%29%5E2%2B3x%3D8 ? You win at life. Link to comment Share on other sites More sharing options...
pygmalion_effect 776 Posted October 30, 2014 Share Posted October 30, 2014 Can we make a homework help thread? Link to comment Share on other sites More sharing options...
Unit 530 Posted October 30, 2014 Share Posted October 30, 2014 Can we make a homework help thread?I could but is it needed? lol. Link to comment Share on other sites More sharing options...
pygmalion_effect 776 Posted October 30, 2014 Share Posted October 30, 2014 I could but is it needed? lol. It would be helpful lol Link to comment Share on other sites More sharing options...
Vividemix3 1,697 Posted October 31, 2014 Author Share Posted October 31, 2014 Do exactly what silktiger said. 2. Go to 'Window' and set your X-min as -5, X-max as 5. Y-min as -0, Y-max as 10. Scales at 1. 3. Click 'Graph'. 4. Then Click 2nd --> 'Trace'. 5. Select 'Intersect'. Press 'Enter' button twice. You should find it. x = 1.228 or -1.473 That's incorrect though. Ugh so sorry for being so late but I did this and I got x=1.8. Instead of pressing the button twice, I had to press it three times. Link to comment Share on other sites More sharing options...
Athena 21,718 Posted October 31, 2014 Share Posted October 31, 2014 Ugh so sorry for being so late but I did this and I got x=1.8. Instead of pressing the button twice, I had to press it three times. You still got 1.8 or did you press the three buttons and get 1.2? Link to comment Share on other sites More sharing options...
Vividemix3 1,697 Posted October 31, 2014 Author Share Posted October 31, 2014 You still got 1.8 or did you press the three buttons and get 1.2? I still got 1.8 D: Link to comment Share on other sites More sharing options...
Athena 21,718 Posted October 31, 2014 Share Posted October 31, 2014 I still got 1.8 D: Are you using a graphing calc? Are you putting in parentheses when you put in the exponent? Ex. ln(x+3)^(2 +3x) I fixed the problem in the previous link that some posted before by adding parentheses and got the right answer. http://www.wolframalpha.com/input/?i=+ln%28x%2B3%29%5E%282%2B3x%29%3D8 Link to comment Share on other sites More sharing options...
Vividemix3 1,697 Posted October 31, 2014 Author Share Posted October 31, 2014 Are you using a graphing calc? Are you putting in parentheses when you put in the exponent? Ex. ln(x+3)^(2 +3x) I fixed the problem in the previous link that some posted before by adding parentheses and got the right answer. http://www.wolframalpha.com/input/?i=+ln%28x%2B3%29%5E%282%2B3x%29%3D8 The 3x isn't part of the exponent though. It's supposed to be ln(x+3)^2 +3x. And yeah I am using a graphing calculator. Link to comment Share on other sites More sharing options...
Athena 21,718 Posted October 31, 2014 Share Posted October 31, 2014 The 3x isn't part of the exponent though. It's supposed to be ln(x+3)^2 +3x. And yeah I am using a graphing calculator. Then you are correct then. I thought the 3x was part of the exponent the whole time :/ Link to comment Share on other sites More sharing options...
Vividemix3 1,697 Posted October 31, 2014 Author Share Posted October 31, 2014 Then you are correct then. I thought the 3x was part of the exponent the whole time :/ Oh sorry xD. Thank you for helping me though. You really saved me. Link to comment Share on other sites More sharing options...
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