Find expert advice and community support for all your questions on IDNLearn.com. Our community is here to provide the comprehensive and accurate answers you need to make informed decisions.

Solve for [tex]\(x\)[/tex]:

[tex]\[x^2 + 4x + y^2 - 5 = 0\][/tex]


Sagot :

Sure, let's solve the equation [tex]\( x^2 + 4x + y^2 - 5 = 0 \)[/tex] step by step.

### Step 1: Understanding the Equation
We start with the equation:
[tex]\[ x^2 + 4x + y^2 - 5 = 0 \][/tex]
This is a standard form of a conic section, specifically a circle, ellipse, parabola, or hyperbola.

### Step 2: Grouping the Variables
Let's focus on grouping the [tex]\( x \)[/tex] and [tex]\( y \)[/tex] terms:
[tex]\[ x^2 + 4x + y^2 - 5 = 0 \][/tex]

### Step 3: Completing the Square for x
To make it easier to solve for [tex]\( y \)[/tex], we can complete the square for the [tex]\( x \)[/tex]-terms:
[tex]\[ x^2 + 4x = (x + 2)^2 - 4 \][/tex]
So, substituting this back into the original equation, we get:
[tex]\[ (x + 2)^2 - 4 + y^2 - 5 = 0 \][/tex]
[tex]\[ (x + 2)^2 + y^2 - 9 = 0 \][/tex]

### Step 4: Isolating the [tex]\( y^2 \)[/tex] Term
Rearrange the equation to isolate the [tex]\( y^2 \)[/tex] term:
[tex]\[ (x + 2)^2 + y^2 = 9 \][/tex]

### Step 5: Solving for [tex]\( y \)[/tex]
Now isolate [tex]\( y^2 \)[/tex]:
[tex]\[ y^2 = 9 - (x + 2)^2 \][/tex]

### Step 6: Taking the Square Root
To solve for [tex]\( y \)[/tex], take the square root of both sides:
[tex]\[ y = \pm \sqrt{9 - (x + 2)^2} \][/tex]

### Step 7: Simplify the Solution
Express the solutions for [tex]\( y \)[/tex] more clearly:
Let [tex]\( (x + 2) = z \)[/tex], then the formula becomes:
[tex]\[ y = \pm \sqrt{9 - z^2} \][/tex]

Substitute [tex]\( z \)[/tex] back:
[tex]\[ y = \pm \sqrt{9 - (x + 2)^2} \][/tex]

### Step 8: Factorize the Inner Term
Notice that [tex]\( 9 - (x + 2)^2 \)[/tex] should be refactored:
[tex]\[ 9 - (x + 2)^2 = 9 - (x^2 + 4x + 4) \][/tex]
[tex]\[ = -x^2 - 4x + 5 = -1((x - 1)(x + 5))\][/tex]

Thus we have:
[tex]\[ y = \pm \sqrt{-(x - 1)(x + 5)}\][/tex]

### Final Answer
Hence, the solutions for the equation [tex]\( x^2 + 4x + y^2 - 5 = 0 \)[/tex] are:
[tex]\[ y = \pm \sqrt{-(x - 1)(x + 5)} \][/tex]