Quotient Rule – Calculus Tutorials - Harvey Mudd College
math.hmc.edu › quotient-ruleQuotient Rule. Let f and g be differentiable at x with g ( x) ≠ 0. Then f / g is differentiable at x and. [ f ( x) g ( x)] ′ = g ( x) f ′ ( x) − f ( x) g ′ ( x) [ g ( x)] 2. Proof of Quotient Rule. We will apply the limit definition of the derivative: f ′ ( x) = lim Δ x → 0 f ( x + Δ x) − f ( x) Δ x. h ′ ( x) = [ f ( x) g ( x)] ′ = lim h → 0 f ( x + h) g ( x + h) − f ( x) g ( x) h = lim h → 0 1 h f ( x + h) g ( x) − f ( x) g ( x + h) g ( x + h) g ( x) = lim h ...
The Quotient Rule for Derivatives - Calculus
www.subjectcoach.com › tutorials › mathNow use the quotient rule to find: d d x ( tan x) = g ( x) f ′ ( x) − f ( x) g ′ ( x) ( g ( x)) 2 = ( cos x) ( cos x) − ( sin x) ( − sin x) cos 2 x = cos 2 x + sin 2 x cos 2 x. Someone out there is sure to be wondering how we turn this into s e c 2 x. The answer is that there's a trig identity that tells us that cos 2 x + sin 2 x = 1. So,