Solve the equation
Ans : a = 1 or -6/5
Question : Do we need to include -6/5
Contributed by YC
It is important for you to check if your answers are valid i.e are there any answers you would need to reject?
This is what I called checking for validity of answers.
Ai Ling Ong
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I guess, we do not include -6/5 as there is no such graph of log(-a).
Good answer. Absolutely correct!
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Clearly the domain (admissible values of x for the argument of the function f(x)=lg(x)) of f(x) is (0, \infty). If a=-6/5, then 3a+2 is negative; therefore x=-6/5 is not admissible into the domain of function f(x).