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Algebra->Sequence

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by sairakarim07 » Wed May 08, 2013 12:53 pm
Mario_87 wrote:Hi guys,
I do not understand this question.
In any case what is the best way to deal with these type of questions?

Thank you very much
Regards

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As g(x) = 5x; g(c-d)= 5(c-d) = 5c-5d. again g(C) = 5c and g(d) = 5d. in this circumstances we see that LHS becomes equal RHS.
Hence OA:D
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by Blue_Skies » Wed May 08, 2013 12:57 pm
Mario_87 wrote:Hi guys,
I do not understand this question.
In any case what is the best way to deal with these type of questions?

Thank you very much
Regards

Image
You have to check for each individual function in this case. You can discard each one except 4 by just looking. Answer is D.
1)g(x)=x^3.
LHS :g(c-d)= (c-d) ^ 3.
RHS : g(c)-g(d) = c^3-d^3.
LHS != RHS.

Similarly look for all the other cases only D qualifies as :
LHS : g(c-d) = 5(c-d)= 5c- 5d
RHS : g(c)-g(d) = 5c - 5d.

Hence D.
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by Atekihcan » Wed May 08, 2013 10:51 pm
Actually you don't have to check for all the options if you understand that g(c - d) will be equal to g(c) - g(d) for some function g(x) only if g(x) is linear in nature.

Now have a look at the options.
Only for options B and D, g(x) is linear.
Check only those 2.

B. g(x) = x + 5 ---> g(c - d) = (c - d) + 5 BUT g(c) - g(d) = (c + 5) - (d + 5) = c - d ---> NO

So, D must be the correct answer.

Answer : D
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by Atekihcan » Wed May 08, 2013 10:58 pm
Actually you don't have to check for all the options if you understand that g(c - d) will be equal to g(c) - g(d) for some function g(x) only if g(x) is linear in nature.

Now have a look at the options.
Only for options B and D, g(x) is linear.
Check only those 2.

B. g(x) = x + 5 ---> g(c - d) = (c - d) + 5 BUT g(c) - g(d) = (c + 5) - (d + 5) = c - d ---> NO

So, D must be the correct answer.

Answer : D
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