Which of the following relationships between the slope of the tangent line to a…

MATHEMATICS · Single correct · A Level · Mathematics · Coordinate geometry in the (x y) plane · Coordinate geometry in the (x y) plane

Problem

Which of the following relationships between the slope

m_t

of the tangent line to a differentiable curve at a point and the slope

m_n

of the corresponding normal line at that point is always true, provided

m_t\neq 0

? (a)

m_n=-m_t

(b)

m_n=\dfrac{1}{m_t}

(c)

m_n=-\dfrac{1}{m_t}

(d)

m_n=-m_t^{2}