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Rational inequalities with transformed inputs

It is given that f(x)=x−52x−3f(x)=\dfrac{x-5}{2x-3}. Using an algebraic method, solve the inequality f(x)≤23f(x)\leq\dfrac23.

Hence find the exact range of values of xx for which

(i) f(ln⁡x)≤23f(\ln x)\leq\dfrac23,

(ii) f(∣x+12∣)≤23f\left(\left|x+\dfrac12\right|\right)\leq\dfrac23.

[2013/RI/I/10]

CJC · Discussion · Question 4

First solve for a general input, then substitute each new input into that solution set.

Read the worked solution