Doubt from function

function-domain
hard
sm
trigonometry
unsolved
#1

17,19

#2

For 17, -D/4a should be greater than 6.

#3

Is it A

#4

Yes, getting the same.

#5

Thats C i think so

#6

For 17th?

#7

for 17

#8

Ah yes! Min. Value will be 6.

#9

Check again

#10

What is the ans. man???

#11

"Sir"

#12

Sorry sir.....

#13

#14

Check again it is not correct!

#15

0k let me check...