What is the equation of the line normal to #f(x)=2x^2-x - 1# at #x=5#?
1 Answer
or
#y = -1/19 x + 841/19
Explanation:
Remember
Slope of normal line is
Step 1: Find derivative, to determine the slope of tangent line
#f'(x) = 4x -1#
Step 2: Find the slope of the tangent line
#m= f'(5) = 4(5) -1 = 19#
Slope of normal line is
Step 3 Determine the
#f(5) = 50-5-1#
#f(5) = 44#
Ordered pair
Step 4: Write the equation of the line using point slope formula
#y-44 = -1/19 x +5/19 #
#y = -1/19x + 5/19 +44#
#y = -1/19x +44 5/19 #
or