Find the values of k for which the quadratic equation 9x^2-3kx+k=0 has equal roots
Answers
Answered by
22
for equal roots discriminant =0
D=√[(-3k)^2-4(9k)]=0
square b. s
9k^2=36k
k(9k)=k(36)
k=0.............................................(1)
9k=36
k=4................................................(2)
k=4,0
D=√[(-3k)^2-4(9k)]=0
square b. s
9k^2=36k
k(9k)=k(36)
k=0.............................................(1)
9k=36
k=4................................................(2)
k=4,0
Answered by
5
Answer:
Hey I Am Ritu Priya
Sonar
Here Is Your Answer
Given quadratic equation is
= 9x² + 3kx + 4 = 0
On comparing with standard form of quadratic equation i.e ax² + bx + c =0,a≠0
Here, a = 9 , b= 3k, c= 4
D(discriminant)= b²-4ac
= (3k)² - 4× 9 ×4
= 9k² - 144
Since, roots of given equation are distinct.
D > 0.
= 9k² - 144 > 0
= 9(k² - 16) >0
= (k² - 16) >0 (9≠0)
= k² -4²>0
= (k-4) (k+4) >0
= [ a² - b² = (a-b)(a+b)]
= k > 4 and k< -4
Hence, the value of k is k > 4 and k< -4.
THANKS
Similar questions