The question is composed of two parts:
(a) Use algebrato find the set of valuesof x for which x(x - 5) > 36
I found the answer x < -4, x > 9
The second part is the one I'm having trouble with.
(b) Using your answer to part [a], find the set of values of y for which y^2(y^2 - 5) > 36
I'm not sure how I'm going to use the answer from part 1 in part 2. I'm not sure where to begin answering this question. The answer is y < -3, y > 3
Can someone please explain this to me.
(a) Use algebrato find the set of valuesof x for which x(x - 5) > 36
I found the answer x < -4, x > 9
The second part is the one I'm having trouble with.
(b) Using your answer to part [a], find the set of values of y for which y^2(y^2 - 5) > 36
I'm not sure how I'm going to use the answer from part 1 in part 2. I'm not sure where to begin answering this question. The answer is y < -3, y > 3
Can someone please explain this to me.
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If you set x = y², the solution to part (a) tells you that y² < -4 or y² > 9.
But y² < -4 is impossible because that would imply y² is negative, which is impossible.
Hence y² > 9 is the only possibility and, as you say, the answer is y < -3 or y > 3.
But y² < -4 is impossible because that would imply y² is negative, which is impossible.
Hence y² > 9 is the only possibility and, as you say, the answer is y < -3 or y > 3.
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Glad to help!
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