Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NDA2011MathematicsQuadratic EquationActual

If 3 is the root of the equation x^2-8 x+k=0 , then what is the value of k ?

Options

  1. A-15
  2. B9
  3. C15
  4. D24

Correct answer

C. 15

Step-by-step solution

Since 3 is root of the equation array rlrl & 3^2-8 3+k & =0 & & k & =15 . array

Practice Quadratic Equation on Quantrex Academy →

More from Quadratic Equation

For a given k , what is the minimum value of x^2+kx+k^2 ? 2026If the highest degree coefficient is equal to 1 , then what is the total number of quadratic equations which are unchanged on squaring their roots ? 2026Let and be the roots of the quadratic equation x^2-2bx+c^2=0 where b , c are positive real numbers. Let A be the arithmetic mean of and ; and G be the geometric mean of and . What 2026Consider the following statements : I. x +x+1=0 has two irrational roots. II. 5 x -x-4=0 has two rational roots. Which of the statements given above is/are correct ? 2026For the following two (02) items: Let f(x) = ax^2 + bx + c be a quadratic polynomial such that f(1) = f(4) = 2 . Further, 2 is a root of f(x) = 0 . What is (a + b + c) equal to? 2025For the following two (02) items: Let and be the roots of the quadratic equation x^2 + ( _ 0.5 (a^2))x + ( _ 0.5 (a^2))^4 = 0 , where a^2 1 and _ 0.5 (a^2) > 0 . Further, ^2 = ( _ 2025For the following two (02) items: Let f(x) = ax^2 + bx + c be a quadratic polynomial such that f(1) = f(4) = 2 . Further, 2 is a root of f(x) = 0 . What is the other root of f(x) = 2025If one root of the equation x^2 - kx + k = 0 exceeds the other by 2 3 , then which one of the following is a value of k ? 2025 Full Quadratic Equation list All NDA PYQs