Wednesday

April 16, 2014

April 16, 2014

Posted by **drwls** on Monday, February 19, 2007 at 9:02pm.

df/dx = 8 x^3 - 12 x

When x = 3, the slope is

m = 8*27 - 36 = 180

and the equation of the tangent line is

(y - 228) = 180*(x - 3)

y = 180 x - 540 + 228 = 180 x - 312

wow, that was absolutely correct (i just plugged it into webassign), thanks a lot!!

please just help me to understand the last part though for the test, where did you get the (y-228) = 180*(x-3)?

Find the equation of the line that is tangent to the graph of f(x) = 2x4 - 6x2 + 120 at the point (3, 228).

y=?

The equation for a line with slope m through points x = a and y = b is

(y- b)= m (x - a)

That is where the formula came from.

**Related Questions**

Calculus - at what point is the tangent to f(x)=x^2+4x-1 horizontal? That would ...

Calculus derivative - find the slope m and an equation of the tangent line to ...

Math (Calculus 121) - Consider the following function. f(x) = 7x3 + x2 - 0.08x...

Calculus (Normal Line, please check my work) - The slope of the line normal to ...

Calculus - Derivative Differentiate f(x)=(5x-4)^2 There are two ways to do this...

calculus BC slope - consider the curve in xy-plane by x=e^t and y=te^(-t) for t ...

Calculus - The line that is normal to the curve x^2=2xy-3y^2=0 at(1,1) ...

got a couple of calculus questions - 1. What is the equation of the tangent line...

math - i have more than one question so if u no any of the answers please tell ...

Calculus - How do you find Altitude and slope slope is the derivative of a ...