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

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

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

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

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

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

livelaughlilz
 one year ago
Best ResponseYou've already chosen the best response.1haha 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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2Actually 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.

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

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

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

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

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