3 3 votes Find the inverse function of the following= f(x)=2∙3x+9x log3((√(x+1))+1) log3((√(x+1))-1) log3((√(x-1))+1) log3((√(x+1))-2) Calculus functions engineering-mathematics + – Akriti sood 856 views answer comment Share Follow Print See 1 comment 1 1 comment reply Akriti sood commented Nov 27, 2016 reply Follow flag can someone solve this using Log?? 1 1 replyShare Please log in or register to add a comment.
Best answer 3 3 votes Let 3x = t and f(x) = y, then the given function can be rewritten as : y = 2t + t2 ⇒ y = t2 + 2t + 1 - 1 ⇒ y = (t + 1)2 - 1 ⇒ (t + 1)2 = 1 + y ⇒ t = √ (y + 1) - 1 ⇒ 3x = √ (y + 1) - 1 Now taking log both sides , we have : ⇒ x = log3(√ (y + 1) - 1) Hence now to find inverse , we swap x and y , ⇒ y = log3((√ (x + 1) ) - 1) Hence 2) is the correct answer.. Habibkhan answered Nov 27, 2016 • selected Nov 27, 2016 by Kapil Habibkhan comment Share Follow 0 reply Please log in or register to add a comment.