- #1
erok81
- 464
- 0
Ok, I cannot figure out how to this problem. It is the last on my practice test and have had no real problems with any of these other ones.
I have been using this formula:
[tex]\lim_{x\rightarrow a} \frac{f(x)-f(a)}{x-a}[/tex]
Here is the problem, find the equation of the line tangent to the function at the given point.
[tex]f(x)=2x^3-3[/tex] @ (3,51)
The answers he shows are..
[tex]y=54x-147[/tex] or [tex]y=12x-21[/tex]
I have no clue how he gets those. Well, actually I can't even solve it anyway so that doesn't matter.
I think there might be some easier way using derivatives, but we can't use those yet since we haven't learned them. The only other formula I know of is similar to the one above but involves "h" and I can't figure out how to even use that one.
Someone show me how to this one. It might be because I forgot how to factor cubed stuff but who knows, I am so lost.
Thanks for the help.
I have been using this formula:
[tex]\lim_{x\rightarrow a} \frac{f(x)-f(a)}{x-a}[/tex]
Here is the problem, find the equation of the line tangent to the function at the given point.
[tex]f(x)=2x^3-3[/tex] @ (3,51)
The answers he shows are..
[tex]y=54x-147[/tex] or [tex]y=12x-21[/tex]
I have no clue how he gets those. Well, actually I can't even solve it anyway so that doesn't matter.
I think there might be some easier way using derivatives, but we can't use those yet since we haven't learned them. The only other formula I know of is similar to the one above but involves "h" and I can't figure out how to even use that one.
Someone show me how to this one. It might be because I forgot how to factor cubed stuff but who knows, I am so lost.
Thanks for the help.
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