Gerald's answer to Georgia Jansen's Secondary 4 A Maths Singapore question.
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in part i), indices laws are applied.
in part ii), factorisation of quadratic equation is done to find u, and the negative answer is rejected as 2^x cannot be negative. lg is then applied on both sides to find x. ln can also be used to get the same correct answer.
in part iii), the discriminant of the equation which works out to 4-4k is negative if k<-1, hence there will be no solution in that case.
in part ii), factorisation of quadratic equation is done to find u, and the negative answer is rejected as 2^x cannot be negative. lg is then applied on both sides to find x. ln can also be used to get the same correct answer.
in part iii), the discriminant of the equation which works out to 4-4k is negative if k<-1, hence there will be no solution in that case.
Date Posted:
5 years ago
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