For the equation x^2 + 6x + k = 0 to have no real roots, what must be the condit

Practice Questions

Q1
For the equation x^2 + 6x + k = 0 to have no real roots, what must be the condition on k?
  1. k < 0
  2. k > 0
  3. k = 0
  4. k ≤ 0

Questions & Step-by-Step Solutions

For the equation x^2 + 6x + k = 0 to have no real roots, what must be the condition on k?
  • Step 1: Identify the equation given, which is x^2 + 6x + k = 0.
  • Step 2: Recognize that for a quadratic equation to have no real roots, the discriminant must be less than zero.
  • Step 3: Write down the formula for the discriminant, which is D = b^2 - 4ac. Here, a = 1, b = 6, and c = k.
  • Step 4: Substitute the values into the discriminant formula: D = 6^2 - 4*1*k.
  • Step 5: Simplify the expression: D = 36 - 4k.
  • Step 6: Set the discriminant less than zero for no real roots: 36 - 4k < 0.
  • Step 7: Rearrange the inequality: 36 < 4k.
  • Step 8: Divide both sides by 4 to isolate k: 9 < k.
  • Step 9: Write the final condition: k must be greater than 9.
  • Discriminant – The discriminant of a quadratic equation determines the nature of its roots; if it is less than zero, the equation has no real roots.
  • Quadratic Equation – A quadratic equation is a polynomial equation of the form ax^2 + bx + c = 0, where a, b, and c are constants.
Soulshift Feedback ×

On a scale of 0–10, how likely are you to recommend The Soulshift Academy?

Not likely Very likely