1. Derivate questions

Hi everyone i spent almost two hours on on these two questions that i can't answer. Please Help meee!!!!

1)
Given

(a) 0
(b) 5
(c) - 5

All the answers MUST be points:

Thank you

2. Re: Derivate question

First of all, calculate $\displaystyle f'(x)$. How can you use this to find the answers?

3. Re: Derivate question

Originally Posted by danicloud
Hi everyone i spent almost two hours on this question that i can't answer. Please Help meee!!!!

Given at which point will the curve have slope:

(a) 0
(b) 5
(c) - 5

All the answers MUST be points:

Thank you
Solve f'(x) = 0.

Solve f'(x) = 5.

Solve f'(x) = -5.

I hope you understand that f'(x) is the derivative of f(x) with respect to x. Remember to get the y-coordinate after you have found the value of x (use y = f(x)).

If you need more help, please show all your work and say where you're stuck.

4. Re: Derivate question

Thank you i got that but i am still stuck.

I found that the derivate is 12x-30. When i set it equal to 0 i get 5/2, which i substitute for x and get -73/2. Same thing for 5 and -5. However is still gives me a error

5. Re: Derivate question

Originally Posted by danicloud
Thank you i got that but i am still stuck.

I found that the derivate is 12x-30. When i set it equal to 0 i get 5/2, which i substitute for x and get -73/2. Same thing for 5 and -5. However is still gives me a error
Your first answer is correct: (5/2, -73/2).

However, you have not shown any working for the other two parts so it's impossible to know what your trouble is. My previous reply said to show ALL working.

6. Re: Derivate question

sorry so for 5 i found it to be: (12/35,-10511/1225) while for -5: (25/12,-851/24).

The website marks the answer as wrong

7. Re: Derivate question

Originally Posted by danicloud
sorry so for 5 i found it to be: (12/35,-10511/1225) while for -5: (25/12,-851/24).

The website marks the answer as wrong
Your values for x are wrong. Type out every step you did in finding them (you will most likely see your error during the process - same error for both, by the way).