Find the equation of the line that is tangent to the graph of f and parallel to the given line? Function Line f(x)=2x^2 4x-y+4=0

1 Answer
Feb 10, 2018

The equation is #4x - y - 2=0#

Explanation:

If we convert the equation of the line to slope intercept form, we get:

#4x -y + 4 = 0#
#4x + 4 = y#

Therefore, the slope of this line will be #4#. The slope of the parallel line therefore will be #4#. We will be looking for the value of #x# when the derivative of #f(x)# equals #4#.

#f'(x) = 4x#

Thus

#4 = 4x#

#x= 1#

It follows that #y = 2(1)^2 = 2#

Therefore, the equation of the tangent will be

#y - 2 = 4(x - 1)#

#y = 4x -4 + 2#

#y = 4x - 2#

#0 = 4x - y - 2#

Hopefully this helps!