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The minimum value of (x^(2)+2x+4)/(x+2),...

The minimum value of `(x^(2)+2x+4)/(x+2)`, is

A

0

B

1

C

2

D

3

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The correct Answer is:
To find the minimum value of the function \( y = \frac{x^2 + 2x + 4}{x + 2} \), we can follow these steps: ### Step 1: Set up the equation We start with the function: \[ y = \frac{x^2 + 2x + 4}{x + 2} \] ### Step 2: Cross multiply To eliminate the fraction, we can cross multiply: \[ y(x + 2) = x^2 + 2x + 4 \] This simplifies to: \[ xy + 2y = x^2 + 2x + 4 \] ### Step 3: Rearrange the equation Rearranging the equation gives us: \[ x^2 + 2x - xy + 4 - 2y = 0 \] This can be rewritten as: \[ x^2 + (2 - y)x + (4 - 2y) = 0 \] ### Step 4: Identify coefficients In this quadratic equation in terms of \( x \): - Coefficient of \( x^2 \) (a) = 1 - Coefficient of \( x \) (b) = \( 2 - y \) - Constant term (c) = \( 4 - 2y \) ### Step 5: Use the discriminant condition For \( x \) to have real solutions, the discriminant must be non-negative: \[ D = b^2 - 4ac \geq 0 \] Substituting the values of \( a \), \( b \), and \( c \): \[ (2 - y)^2 - 4(1)(4 - 2y) \geq 0 \] ### Step 6: Simplify the discriminant Expanding the discriminant: \[ (2 - y)^2 - 16 + 8y \geq 0 \] This simplifies to: \[ 4 - 4y + y^2 - 16 + 8y \geq 0 \] Combining like terms gives: \[ y^2 + 4y - 12 \geq 0 \] ### Step 7: Factor the quadratic Factoring the quadratic: \[ (y + 6)(y - 2) \geq 0 \] ### Step 8: Solve the inequality To find the intervals where this inequality holds, we find the roots: - \( y + 6 = 0 \) gives \( y = -6 \) - \( y - 2 = 0 \) gives \( y = 2 \) ### Step 9: Test intervals We test the intervals determined by the roots: 1. \( y < -6 \): both factors negative, product positive. 2. \( -6 < y < 2 \): one factor negative, one positive, product negative. 3. \( y > 2 \): both factors positive, product positive. Thus, the solution to the inequality is: \[ y \leq -6 \quad \text{or} \quad y \geq 2 \] ### Step 10: Determine the minimum value Since we are looking for the minimum value, we find: \[ \text{Minimum value of } y = 2 \] ### Final Answer The minimum value of \( \frac{x^2 + 2x + 4}{x + 2} \) is \( \boxed{2} \).

To find the minimum value of the function \( y = \frac{x^2 + 2x + 4}{x + 2} \), we can follow these steps: ### Step 1: Set up the equation We start with the function: \[ y = \frac{x^2 + 2x + 4}{x + 2} \] ...
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