Question

If the equation `4x^2-3kx+1=0` has equal roots then value of k=?  

(a)`+-2/3`                     (b)`+-1/3` 

(c)` +-3/4`                     (d) `+-4/3` 

 

Answer 1

(d) `+-4/3` 

It is given that the roots of the equation `4x^2-3kx+1=0`  are equal. 

∴` (b^2-4ac)=0` 

⇒` (3k)^2-4xx4xx1=0` 

⇒`9k^2=16` 

⇒`k^2=16/9` 

⇒ `k=+-4/3`