Question

20) The equation x2+4x+k=O has real roots ,when
1)K greater than equal to 4
2)Kless than equal to 4
3)Kless than equal to 0
4)K greater than equal to 0​

Answer 1

20) The equation x2+4x+k=O has real roots ,when

1)K greater than equal to 4

2)Kless than equal to 4

3)Kless than equal to 0

4)K greater than equal to 0

ANSWER

x2−4x+k=0 is of the form ax2+bx+c=0 where a=1b=−4c=k

Roots are equal⇒ Discriminant=0

⇒b2−4ac=0

⇒(−4)2−4×1×k=0

⇒16−4k=0

⇒−4k=−16

∴k=416=4

Answer 2

Answer:

2)k less than equal to 4 is the answer