Problem: Find the inverse for the function 𝑓 ( 𝑥 ) = 3 𝑥 + 1 2 𝑥 − 4 .  Suppose a student writes the following solution. Is it correct? Line 1:   Write 𝑦 = 3 𝑥 + 1 2 𝑥 − 4 and solve for 𝑥 .  Line 2:    𝑦 ( 2 𝑥 − 4 ) = 3 𝑥 + 1   Line 3:   2 𝑥 𝑦 − 4 𝑦 = 3 𝑥 + 1   Line 4:   2 𝑥 𝑦 − 3 𝑥 = 1 + 4 𝑦   Line 5:   𝑥 ( 2 𝑦 − 3 ) = 1 + 4 𝑦   Line 6:   𝑥 = 1 + 4 𝑦 2 𝑦 − 3   Line 7:   Now interchange variables:  𝑦 = 1 + 4 𝑥 2 𝑥 − 3     Line 8:   Therefore   𝑓 − 1 ( 𝑥 ) = 1 + 4 𝑥 2 𝑥 − 3      Line 9:   Simplify:   𝑓 − 1 ( 𝑥 ) = 𝑥 + 4 2 − 3 𝑥       a) Is the above solution correct? If not, in which line is the first error? (If there is more than one error, select the line where the FIRST error occurs.) [ Select ] First error is in Line 2. First error is in Line 9. The solution is correct. First error is in Line 1. First error is in Line 7. First error is in Line 4. First error is in Line 6. First error is in Line 3. First error is in Line 5. First error is in Line 8. b) What is the correct final answer to the problem? [ Select ] y = (x+1) / (2-3x) y = (1+4x) / (1-6x) y = (x+4) / (2-3x) None of the other options y = (1+4x) / (2x-3) c) What is the domain of 𝑓 − 1 ( 𝑥 ) ? [ Select ] All real numbers except 3/2 All real numbers except -4 All real numbers except -1/4 All real numbers except 1/6 All real numbers except 2/3多重下拉选择题

登录即可查看完整答案

我们收录了全球超50000道真实原题与详细解析,现在登录,立即获得答案。

更多留学生实用工具

加入我们,立即解锁 海量真题独家解析,让复习快人一步!