Equation for the tangent line

Sophia1787
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Homework Statement



Find the equation for the tangent line to the curve f(x) = 2x3 - 5x - 3 at
x = 2



Homework Equations


How do i start this? I'm really confused and have an assignment with a bunch of these questions due tomorrow by midnight... if someone could help me that would be greatly appreciated..



The Attempt at a Solution

 
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The derivative f'(x) will give you the slope of the tangent. x and f(x) will give you a point on the curve. If you have a point and a slope, you have the equation for the tangent line, right?
 
One of the very first things you should learn in Calculus is that the derivative at a point is the slope of the tangent line. And even before Calculus you should have learned how to write the equation of a line given a point and the slope.
 
so basically 6x^2-5 ?
 
do i then plug in the 2? and solve?
 
Sophia1787 said:
so basically 6x^2-5 ?
"Basically" what about 6x^2- 5?

Sophia1787 said:
do i then plug in the 2? and solve?
Plug 2 into what? Solve what? Please ask complete questions!

I said before that the derivative at a given value of x is the slope of the tangent line at that x. What is the derivative of your function? What is its value at x= 2?

Now, how do you find the equation of a line through a given point with given slope? (And what "given point" does this line go through?
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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