Question

Find an equation of the tangent line to the graph of the function f defined by the following equation at the indicated point.
(x - y - 1)3 = x; (1, -1)

Answer 1

p=(x1, y1)

tangent line:
y-y1=m(x-x1)

normal line:
y-y1=(-1/m)(x-x1)

where m=slope=y'
(hint: solve for y. Then find y')

http://www.cliffsnotes.com/study_guide/Tangent-and-Normal-Lines.topicArticleId-39909,articleId-39887.html

Answer 2

Ignore the normal line formula. Your question doesn't ask for an equation of the normal line.