Find the equation of the tangent line at f(x)=x at x=4

It's not 1.
:(

f(4) = 4.

dy/dx of 4 is zero.

.

So the answer is 0? I ran out of chances on the problem so I can't try it anymore...

What about f(x) = 5x^2 at x=10?

Of course it's not 1. 1 is a number, and tangent is a line. It's a line with the slope of 1, namely the line y = x. (Yes, a line is it's own tangent line.)


Derivative of that function is f'(x) = 10x, so the tangent line at x=10 has the slope of 10, so you know that the equation of the tangent is y = 10x + c, where c is yet to be determined. You can determine the value of c from te fact that it is a y-intercept of the tangent on the function f(x) = 5x^2 at x=10, which means that point (10,f(10)) i.e. (10,500) lies on the line y = 10x + c. So, we have 500 = 10*10 + c, hence c = 400.

The tangent is y = 10x + 400.

I can't go back to that problem now. What about the other one I posted?

nevermind, I used up my damn two attempts again.

If g(x) is an odd function and g-prime(14) = 8, what is g-prime(-14)?

Do you know how to do these?

Substitute the number into f(x), evaluate, derive, substitute, evaluate.

I'm sorry but this is clearly your own homework and we can't do it for you. If you had asked for help with the concept, I would have gladly given you examples to learn from. How about you crack open that text book and learn from that instead. As I understand it, calculus at that level is very procedural.

EDIT: In regards to your question - http://en.wikipedia.org/wiki/Even_and_odd_functions

Do you think I haven't looked through my textbook? Obviously that was the first place I went. There are no examples or anything on this type of problem.

Look at the edit.


Assuming that by g-prime you mean derivative of g, it should be enough to say that derivative of an odd function is an even function.

btw what does MOAR stand for?

MOAR=more.
The answer was 8.

If you say so


Yes, I know