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Comment on Functions f and g
Dear Sir ,
Would Please care to explain the following explanation, which i found in greprep question.
GIVEN y = 5x^2 − 10x + 7y
QUANTITY A -----X QUANTITY B ----- Y
This is an interesting one! There are many tedious ways to solve this one. The one highlighted here is a clever and fast way to solve this kind of questions. Consider the expression (y−x) which it can be derived from the expression of y given, y − x = 5x^2 − 11x + 7 = f(x)
This quadratic function has no real roots since b2−4ac<0 and since a>0 f(x) is always greater than 0 i.e, (y−x)>0 or y>x.
Therefore the correct choice is B.
The correct answer B
Regards
Shubham
Are you sure you transcribed
Are you sure you transcribed the question correctly?
If y = 5x^2 − 10x + 7y, then we can say -6y = 5x^2 − 10x
Or, we can write: y = (5x^2 − 10x)/(-6)
At this point, we can see that when x = 0, y = 0 also
Since it's possible that the two quantities can be equal, the correct answer is either C or D. The answer cannot be B, as you suggest.
Hi Brent, i'm struggling to
Thanks!
You're not alone. In fact, I
You're not alone. In fact, I distinctly remember not like function notation when I first encountered it.
Here are a couple more pages that might help:
- https://mathbitsnotebook.com/Algebra1/Functions/FNNotationEvaluation.html
- https://www.thatquiz.org/tq/previewtest?H/M/M/O/ISMT1391098730
Cheers,
Brent