Quantcast

Got Homework?

Connect with other students for help. It's a free community.

  • across
    MIT Grad Student
    Online now
  • laura*
    Helped 1,000 students
    Online now
  • Hero
    College Math Guru
    Online now

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

sandra

Can someone help me with basic derivatives: 3x^2 + 5x + 5?

  • 2 years ago
  • 2 years ago

  • This Question is Closed
  1. Ana2
    Best Response
    You've already chosen the best response.
    Medals 5

    6x + 5

    • 2 years ago
  2. A_clan
    Best Response
    You've already chosen the best response.
    Medals 0

    3(2X) + 5

    • 2 years ago
  3. clauixx
    Best Response
    You've already chosen the best response.
    Medals 0

    6x+5

    • 2 years ago
  4. Ana2
    Best Response
    You've already chosen the best response.
    Medals 5

    The rules are: derivative of x^n = n * x^(n-1) derivative of sum is the sum of the derivatives. derivative of a constant times a function equals the constant times the derivative of the function.

    • 2 years ago
  5. shadowfiend
    Best Response
    You've already chosen the best response.
    Medals 2

    The approach is pretty straightforward -- \(x^2\) on its own derives to 2x. Since it has a 3 in front of it, we get 3(2x), as above. x derives to \(x^0\), which is the same as 1. Since it has a 5 in front of it, we get 5, as above. 5 disappears, because it is a constant and the derivative of a constant is 0.

    • 2 years ago
  6. Ana2
    Best Response
    You've already chosen the best response.
    Medals 5

    So d/dx (3x^2 +5x + 5) = d/dx (3x^2) + d/dx (5x) + d/dx (5) = 3* d/dx (x^2) + 5 * d/dx (x) + 0 = 3 * 2 x + 5 * 1 = 6x + 5

    • 2 years ago
  7. amistre64
    Best Response
    You've already chosen the best response.
    Medals 0

    \[\lim_{h\rightarrow 0}\ \frac{f(x+h)-f(x)}{h}\] \[(3(x+h)^2 +5(x+h) +5)-(3x^2 +5x +5)//h\] \[(3(x^2+2xh+h^2) +5x+5h +5 -3x^2 -5x -5)//h\] \[3x^2+6xh+3h^2 +5x+5h +5 -3x^2 -5x -5)//h\] \[\frac{6xh+3h^2+5h}{h}\] \[\lim_{h\rightarrow0}\ 6x+3h+5\ =\ 6x+5\]

    • 2 years ago
  8. amistre64
    Best Response
    You've already chosen the best response.
    Medals 0

    the long version lets you appreciate the shortcut rules ;)

    • 2 years ago
    • Attachments:

See more questions >>>

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
  • 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.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.