if X is real, find minimum of x^2-2x+2/x^2+3x+9
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Answered by
8
""" ❤️ Answer ❤️ """
Let
y=
x 2
x 2
.
⇒ y(x
2
+ 2x+ 3)=
x 2
14x+ 9
⇒ (y− 1)x
2
+ 2(y− 7)x+ 3y− 9= 0
Since, x is real, so discriminant of above equation will be greater than or equal to 0.
D≥ 0
⇒ 4(y− 7)
2
− 4(y− 1)(3y− 9)≥ 0
⇒ (y− 7)
2
− (y− 1)(3y− 9)≥ 0
⇒
y 2
49− 14y− 3(y
2
− 4y+ 3)≥ 0
⇒ −2y
2
− 2y+ 40≥ 0
⇒
y 2
y− 20≤ 0
⇒
y 2
5y− 4y− 20≤ 0
⇒ y(y+ 5)− 4(y+ 5)≤ 0
⇒ (y+ 5)(y− 4)≤ 0
⇒ y∈ [−5,4]
So, the maximum value of y is 4 and minimum value of y is -4
Answered by
0
Answer:
x²-2x+2/x²+3x+9
=9+x³+2/x²
-x=11
=x+11
Hope it helps
Brainliest
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