A community for students.
Here's the question you clicked on:
 0 viewing

This Question is Closed

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

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

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

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

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

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

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

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

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

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

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

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

livelaughlilz
 2 years 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
 2 years ago
Best ResponseYou've already chosen the best response.0Yes^ @livelaughlilz

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

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

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

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

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

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

mathmate
 2 years 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
 2 years ago
Best ResponseYou've already chosen the best response.1well b^24ac is also the discriminant...

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

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

mathmate
 2 years 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
 2 years ago
Best ResponseYou've already chosen the best response.1i'm going to close this question now. thanks everyone!
Ask your own question
Sign UpFind more explanations on OpenStudy
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.