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Question

Determine the nature of the roots of the quadratic equation $3x^2 + 2x + 5 = 0$.

The correct answer is
Complex Roots (Imaginary Roots)

Finding the Nature of Roots for $3x^2 + 2x + 5 = 0$

To determine the nature of the roots of a quadratic equation, we examine its discriminant. The given quadratic equation is:

$$3x^2 + 2x + 5 = 0$$

Understanding the Discriminant

A quadratic equation is generally represented in the form:

$$ax^2 + bx + c = 0$$

Where $a$, $b$, and $c$ are coefficients. The discriminant, denoted by $\Delta$, is calculated using the formula:

$$\Delta = b^2 - 4ac$$

The value of the discriminant helps us classify the roots:

  • If $\Delta > 0$, the roots are real and distinct.
  • If $\Delta = 0$, the roots are real and equal.
  • If $\Delta < 0$, the roots are complex (or imaginary) and not real.

Calculating the Discriminant

For the given equation $3x^2 + 2x + 5 = 0$, we identify the coefficients:

  • $a = 3$
  • $b = 2$
  • $c = 5$

Now, let's substitute these values into the discriminant formula:

$$\Delta = (2)^2 - 4(3)(5)$$

First, calculate $b^2$:

$$\Delta = 4 - 4(3)(5)$$

Next, calculate $4ac$:

$$4(3)(5) = 12 \times 5 = 60$$

Now, subtract $4ac$ from $b^2$:

$$\Delta = 4 - 60$$

$$\Delta = -56$$

Interpreting the Result

The calculated discriminant is $\Delta = -56$. Since $-56$ is less than $0$ ($\Delta < 0$), the roots of the quadratic equation $3x^2 + 2x + 5 = 0$ are complex (imaginary).

Conclusion

Comparing our result with the given options, the nature of the roots is Complex Roots (Imaginary Roots).

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Important Questions from Quadratic equation

  1. What number should be subtracted from x3−4x2−8x+11 to make the number divisible by (x+2)?

  2. Find the value of K if the quadratic equations $2x^2 + Kx + 8 = 0$ and $3x^2 + 4x + 12 = 0$ have both roots common.
  3. If sum and product of the roots of a quadratic equation are $(4-3\sqrt{2})$ and -28, respectively, then find the quadratic equation.
  4. If the quadratic equations $4x^2 + bx + 3 = 0$ and $8x^2 + 4x + c = 0$ have both the roots common, find the values for b and c, respectively.
  5. Find roots of $5m^2 + 18m + 16 = 0$
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