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saifoo.khanBest ResponseYou've already chosen the best response.0
\[\Large 7^{x^24x+7}\]Like this?
 one year ago

saifoo.khanBest ResponseYou've already chosen the best response.0
@mathmate @UnkleRhaukus
 one year ago

saifoo.khanBest ResponseYou've already chosen the best response.0
Minimum value should be there where dy/dx = 0.
 one year ago

livelaughlilzBest ResponseYou've already chosen the best response.1
what do you mean by the "d"?
 one year ago

saifoo.khanBest ResponseYou've already chosen the best response.0
In other words minimum value occurs where the derivative of the function is equal to zero.
 one year ago

livelaughlilzBest ResponseYou've already chosen the best response.1
isn't derivatives calculus? i haven't learned that yet and i don't think we're expected to know it to solve this problem
 one year ago

saifoo.khanBest ResponseYou've already chosen the best response.0
http://www.mememaker.net/static/images/templates/14288.jpg
 one year ago

livelaughlilzBest ResponseYou've already chosen the best response.1
haha i was thinking about it and wouldn't it be one over infinity? because if x^24x+7 was negative infinity than 7^(x^24x+7) would be 1/infinity
 one year ago

mathmateBest ResponseYou've already chosen the best response.2
Hint: 7^x is an increasing function. So if we minimize x, 7^x is also a minimum.
 one year ago

mathmateBest ResponseYou've already chosen the best response.2
x^24x+7 cannot be at inf. It is a parabola concave upwards.!
 one year ago

saifoo.khanBest ResponseYou've already chosen the best response.0
And are we going to try that by trial and error? @mathmate
 one year ago

KingGeorgeBest ResponseYou've already chosen the best response.1
No, we need to simply find the vertex of the parabola to find the minimum value of the parabola.
 one year ago

mathmateBest ResponseYou've already chosen the best response.2
Good point!] @livelaughlilz can you take it from here?
 one year ago

mathmateBest ResponseYou've already chosen the best response.2
Completing the squares will do the job.
 one year ago

livelaughlilzBest ResponseYou've already chosen the best response.1
yeah the vertex of the parabola is (2,3)
 one year ago

mathmateBest ResponseYou've already chosen the best response.2
x^24x+7=(x2)^2+3 so the vertex is at (2,3)
 one year ago

saifoo.khanBest ResponseYou've already chosen the best response.0
http://i1.kymcdn.com/entries/icons/original/000/009/993/tumblr_m0wb2xz9Yh1r08e3p.jpg
 one year ago

mathmateBest ResponseYou've already chosen the best response.2
Good job livelaughlilz! Speed+accuracy!
 one year ago

mathmateBest ResponseYou've already chosen the best response.2
I like his movies! :)
 one year ago

livelaughlilzBest ResponseYou've already chosen the best response.1
oh so the answer is 343. the lowest value of x is 2, and if you plug it in you get 7^3=343
 one year ago

saifoo.khanBest ResponseYou've already chosen the best response.0
Yes^ @livelaughlilz
 one year ago

saifoo.khanBest ResponseYou've already chosen the best response.0
@mathmate : haha, nice. My brother just love his movies. i don't. :/
 one year ago

mathmateBest ResponseYou've already chosen the best response.2
Nevermind, I was out of my mind. Yes, 7^3=343
 one year ago

saifoo.khanBest ResponseYou've already chosen the best response.0
You were thinking about Jackie Chan. :D
 one year ago

KingGeorgeBest ResponseYou've already chosen the best response.1
As a sidenote @mathmate, you can find the xcoordinate of the vertex using the formula \[v_x=\frac{b}{2a}\]
 one year ago

mathmateBest ResponseYou've already chosen the best response.2
Thank you for the defence, even though it was a lame one! Good thinking! :)
 one year ago

saifoo.khanBest ResponseYou've already chosen the best response.0
I simply love this method. Satellite73 taught me this. b/2a
 one year ago

livelaughlilzBest ResponseYou've already chosen the best response.1
to add onto @KingGeorge the ycoordinate of the vertex is [(b^24ac)/(4a)]
 one year ago

mathmateBest ResponseYou've already chosen the best response.2
Thank you @KingGeorge, my memory is limited and sometimes defective. But thanks for the shortcut anyway!
 one year ago

livelaughlilzBest ResponseYou've already chosen the best response.1
you can figure all that out by completing the square of y=ax^2+bx+c
 one year ago

livelaughlilzBest ResponseYou've already chosen the best response.1
and making y=ax^2+bx+c into vertex form
 one year ago

mathmateBest ResponseYou've already chosen the best response.2
Actually I know the b/2a part, that's how I get to do the completing the square. It's just I never managed to memorize the [(b^24ac)/(4a)] part.
 one year ago

livelaughlilzBest ResponseYou've already chosen the best response.1
well b^24ac is also the discriminant...
 one year ago

saifoo.khanBest ResponseYou've already chosen the best response.0
@livelaughlilz is a boss at this.
 one year ago

mathmateBest ResponseYou've already chosen the best response.2
Perhaps from this time on I will remember. Practice makes perfect! :)
 one year ago

mathmateBest ResponseYou've already chosen the best response.2
Actually what I do is finding it by c(b/2a)^2, which is exactly what we do when we complete the square.
 one year ago

livelaughlilzBest ResponseYou've already chosen the best response.1
i'm going to close this question now. thanks everyone!
 one year ago
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