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secondary 4 | A Maths
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sos...i think this question is about quadratic function I don't know how to do
Date Posted: 7 years ago
Views: 382
Not too sure about this question but i'll make a smart guess.
Proving that the function is positive basically means that you have to prove that the function will always be equal to or greater than zero.
Since x and y are real, they can either be positive or negative integers. Since x and y are squared in the function, 4x^2 +10y^2 will definitely give you a positive number.
The sum of 4x^2 + 10y^2 will be greater than the effect of -12xy, which may or may not be positive depending on the values of x and y. If both x and y are positive, -12xy will negative. If one positive one negative, -12xy will be positive so on and forth.
Hence, 4x^2 -12xy + 10y^2 will always be equal to or greater than zero and is hence positive.
Proving that the function is positive basically means that you have to prove that the function will always be equal to or greater than zero.
Since x and y are real, they can either be positive or negative integers. Since x and y are squared in the function, 4x^2 +10y^2 will definitely give you a positive number.
The sum of 4x^2 + 10y^2 will be greater than the effect of -12xy, which may or may not be positive depending on the values of x and y. If both x and y are positive, -12xy will negative. If one positive one negative, -12xy will be positive so on and forth.
Hence, 4x^2 -12xy + 10y^2 will always be equal to or greater than zero and is hence positive.
Thank you very much!
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Thank you very much
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