English

If X = − 1 2 ,Is a Solution of the Quadratic Equation 3 X 2 + 2 K X − 3 = 0 ,Find the Value of K.

Advertisements
Advertisements

Question

If \[x = - \frac{1}{2}\],is a solution of the quadratic equation \[3 x^2 + 2kx - 3 = 0\] ,find the value of k.

Answer in Brief
Advertisements

Solution

Since,  \[x = - \frac{1}{2}\],is a solution of the quadratic equation  \[3 x^2 + 2kx - 3 = 0\]

So, it satisfies the given equation.

\[\therefore 3 \left( - \frac{1}{2} \right)^2 + 2k\left( - \frac{1}{2} \right) - 3 = 0\]

\[ \Rightarrow \frac{3}{4} - k - 3 = 0\]

\[ \Rightarrow k = \frac{3}{4} - 3\]

\[ \Rightarrow k = \frac{3 - 12}{4}\]

\[ \Rightarrow k = - \frac{9}{4}\]

Thus, the value of k is \[- \frac{9}{4}\].

shaalaa.com
  Is there an error in this question or solution?
Chapter 4: Quadratic Equations - Exercise 4.14 [Page 82]

APPEARS IN

R.D. Sharma Mathematics [English] Class 10
Chapter 4 Quadratic Equations
Exercise 4.14 | Q 15 | Page 82

RELATED QUESTIONS

Solve for x

`(2x)/(x-3)+1/(2x+3)+(3x+9)/((x-3)(2x+3)) = 0, x!=3,`


Find the roots of the following quadratic equation by factorisation: 

2x2 + x – 6 = 0


Solve the following quadratic equations by factorization:

6x2 + 11x + 3 = 0


A two digit number is 4 times the sum of its digits and twice the product of its digits. Find the number.


Sum of the areas of two squares is 640 m2. If the difference of their perimeters is 64 m. Find the sides of the two squares.


Solve:

`1/p + 1/q + 1/x = 1/(x + p + q)`


Solve each of the following equations by factorization:  

`x=(3x+1)/(4x)` 


Solve the following quadratic equations by factorization: 

(x + 1) (2x + 8) = (x+7) (x+3) 


Solve the following quadratic equation for x:

x2 − 4ax − b2 + 4a2 = 0


If \[1 + \sqrt{2}\] is a root of a quadratic equation will rational coefficients, write its other root.


If one of the equation ax2 + bx + c = 0 is three times times the other, then b2 : ac =


Solve the following : `("x" - 1/2)^2 = 4`


Find two consecutive positive even integers whose squares have the sum 340.


Five years ago, a woman’s age was the square of her son’s age. Ten years hence, her age will be twice that of her son’s age. Find:

  1. the age of the son five years ago.
  2. the present age of the woman.

A shopkeeper purchases a certain number of books for Rs. 960. If the cost per book was Rs. 8 less, the number of books that could be purchased for Rs. 960 would be 4 more. Write an equation, taking the original cost of each book to be Rs. x, and Solve it to find the original cost of the books.


Solve the following equation by factorization

21x2 – 8x – 4 = 0


Solve the following equation by factorization

(x – 4)2 + 52 = 132   


Solve the following equation by factorization

`x/(x - 1) + (x - 1)/x = 2(1)/(2)`


The hotel bill for a number of people for an overnight stay is Rs. 4800. If there were 4 more, the bill each person had to pay would have reduced by Rs. 200. Find the number of people staying overnight. 


Solve the following equation by factorisation :

x(x + 1) + (x + 2)(x + 3) = 42


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×