A community for students.
Here's the question you clicked on:
 0 viewing
anonymous
 3 years ago
If f(x) is continuous and differentiable and f(x) = ... then b?
f(x) =
{ax^4 + 5x, x< or = 2
{bx^2  3x, x> 2,
then b = ?
Help pls
anonymous
 3 years ago
If f(x) is continuous and differentiable and f(x) = ... then b? f(x) = {ax^4 + 5x, x< or = 2 {bx^2  3x, x> 2, then b = ? Help pls

This Question is Closed

myininaya
 3 years ago
Best ResponseYou've already chosen the best response.11st set these two expressions equal to each other: \[\lim_{x \rightarrow 2^}f(x)=\lim_{x \rightarrow 2^+}f(x)\]

myininaya
 3 years ago
Best ResponseYou've already chosen the best response.12nd set these two expressions equal to each other: \[\lim_{x \rightarrow 2^}f'(x)=\lim_{x \rightarrow 2^+}f'(x)\]

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0What should I do after that? Add those two equations together?

myininaya
 3 years ago
Best ResponseYou've already chosen the best response.1You will have a system of equations to solve just like from algebra class.

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0Well I got, 4a  10 = 4b  6 and then 32 + 5 = 4b  3. Is that correct?

myininaya
 3 years ago
Best ResponseYou've already chosen the best response.1The first equation on the left hand side you have 4a10 I think it should be 16a+10. What happen to a in the second expression?

myininaya
 3 years ago
Best ResponseYou've already chosen the best response.1\[a(2)^4+5(2)=b(2)^23(2) \text{ first equation }\]

myininaya
 3 years ago
Best ResponseYou've already chosen the best response.1\[4a(2)^3+5=2b(2)3 \text{ second equation }\]

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0Wait isn't it a(2)^4 + 5 (2) since the limit is coming from the left side?

myininaya
 3 years ago
Best ResponseYou've already chosen the best response.1It isn't approaching 2. It is approaching 2.

myininaya
 3 years ago
Best ResponseYou've already chosen the best response.1You have the left is just approaching 2 from the left. You have the right is just approaching 2 from the right. Either way they are both still approaching 2 and not some other number.

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0Ahh ok I got it :) After I get these 2 equations then what should I do afterward?

myininaya
 3 years ago
Best ResponseYou've already chosen the best response.1Have you ever solved a system of two linear equations?

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0Yes, like 4 years ago haha.

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.016a + 10 4b  6 32a + 5 4b  3 ( Can't I just substitute it and then solve it) ?

myininaya
 3 years ago
Best ResponseYou've already chosen the best response.1You can put them both in ax+by=c form if you want. Like if we had something like 2x+3y=1 2x+3y=1 This system is already set up for elimination. Add the equations together and solve for y first would be my strategy. 6y=2 y=2/6=1/3 Then plug into one of the other equations and solve for x.

myininaya
 3 years ago
Best ResponseYou've already chosen the best response.1Or this system: 3x6y=2 x+y=2 This one isn't set up for elimination. But you could multiply the bottom equation by 3 so we would have it setup for elmination. 3x6y=2 3x3y=6 add 9y=4 y=4/9 and then so on to find x.

myininaya
 3 years ago
Best ResponseYou've already chosen the best response.1\[a(2)^4+5(2)=b(2)^23(2) \text{ first equation }\] \[16a+10=4b6\] \[16a4b=16 \text{ rewrote the equation 1} \]

myininaya
 3 years ago
Best ResponseYou've already chosen the best response.1Do you think you can rewrite equation 2 in that form?

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.032a  4b = 8 ( 2nd equation right) right?

myininaya
 3 years ago
Best ResponseYou've already chosen the best response.1So we have 16a4b=16 32a4b=8

myininaya
 3 years ago
Best ResponseYou've already chosen the best response.1If we multiply the second or even the first (just not both of them) by 1, then we can set this up for elimination method.

myininaya
 3 years ago
Best ResponseYou've already chosen the best response.1I'm trying to eliminate b. (you could go for a but I prefer working with smaller numbers)

myininaya
 3 years ago
Best ResponseYou've already chosen the best response.1So 16a+4b=16 32a4b=8 add the equations together and what do we get?

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0I got the final answer of 6 for b. Is that right?

anonymous
 3 years ago
Best ResponseYou've already chosen the best response.0yayyy, you should just be my tutor haha. Thank you so much :D
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.