Question

Does f(x)=-5x^2+5x+34 have a minimum value or maximum value?

Answer 1

@orbie
first we are going to take the derivative
and put the derivative equal to zero in order to determine the critical point of a function

Answer 2

@orbie
can u determine the critcal points?

Answer 3

Would it be (0,34)?

Answer 4

After derivative is where we get the x coordinates and after that we look for the y coordinates by substisusing in the original equation?

Answer 5

@kay-jay
after the first derivative, we going to see whether critical point will give us maximum value or minimum value
In order to check whether it is max or min, we will take the second derivative of function
if f ''(x)<0 , then critical point is going to give us the maximum value of function
if f ''(x) >0 , then critical point is going to give us the minimum value

Answer 6

So would it be minimum?

Answer 7

oh... yep. thnx but when looking for the turning points which equations do we use for the y coordinates?

Answer 8

@orbie Iska derivative nikal lo. Phir check karna ki uska zero hai ki nahi.

Answer 9

Samajh aaya?

Answer 10

Kuch bologe bhi?

Answer 11

@ParthKohli I don't understand what you have typed.

Answer 12

@orbie Why?

Answer 13

Well, sorry, I don't know English. @shubhamsrg may assist you.

Answer 14

enlish kya hota hai ?

Answer 15

@shubhamsrg It's a language which I don't really know about. Only heard of it.

Answer 16

Please concentrate on his question -_-

Answer 17

@orbie OK, leaving everything else apart, do you know what a derivative is?

Answer 18

@orbie remember this for questions like this :
is coefficient of x^2 < 0 , then it has a max value
else vice versa

Answer 19

So it would be maximum instead?

Answer 20

@shubhamsrg Nice tricks :'-)

Answer 21

yes, maximum .
since -5<0
though you'll need derivatives to prove this, as everyone was doing above

Answer 22

Right, it makes sense. Thank you guys!

Answer 23

definately maxima will happen to this curve,it's common sense ,peak will be formed i.e. parabola is opening downward ,no need for calulus & all stuff