Key Equations

Key Equations

Difference quotient Q=f(x)−f(a)x−aQ=f(x)−f(a)x−a
Difference quotient with increment hh Q=f(a+h)−f(a)a+h−a=f(a+h)−f(a)hQ=f(a+h)−f(a)a+h−a=f(a+h)−f(a)h
Slope of tangent line mtan=limx→af(x)−f(a)x−amtan=limx→af(x)−f(a)x−a
mtan=limh→0f(a+h)−f(a)hmtan=limh→0f(a+h)−f(a)h
Derivative of f(x)f(x) at aa f′(a)=limx→af(x)−f(a)x−af′(a)=limx→af(x)−f(a)x−a
f′(a)=limh→0f(a+h)−f(a)hf′(a)=limh→0f(a+h)−f(a)h
Average velocity vave=s(t)−s(a)t−avave=s(t)−s(a)t−a
Instantaneous velocity v(a)=s′(a)=limt→as(t)−s(a)t−av(a)=s′(a)=limt→as(t)−s(a)t−a
The derivative function f′(x)=limh→0f(x+h)−f(x)hf′(x)=limh→0f(x+h)−f(x)h
Derivative of sine function ddx(sinx)=cosxddx(sinx)=cosx
Derivative of cosine function ddx(cosx)=−sinxddx(cosx)=−sinx
Derivative of tangent function ddx(tanx)=sec2xddx(tanx)=sec2x
Derivative of cotangent function ddx(cotx)=−csc2xddx(cotx)=−csc2x
Derivative of secant function ddx(secx)=secxtanxddx(secx)=secxtanx
Derivative of cosecant function ddx(cscx)=−cscxcotxddx(cscx)=−cscxcotx
The chain rule h′(x)=f′(g(x))g′(x)h′(x)=f′(g(x))g′(x)
The power rule for functions h′(x)=n(g(x))n−1g′(x)h′(x)=n(g(x))n−1g′(x)
Inverse function theorem (f−1)′(x)=1f′(f−1(x))(f−1)′(x)=1f′(f−1(x)) whenever f′(f−1(x))≠0f′(f−1(x))≠0 and f(x)f(x) is differentiable.
Power rule with rational exponents ddx(xm/n)=mnx(m/n)−1.ddx(xm/n)=mnx(m/n)−1.
Derivative of inverse sine function ddxsin−1x=11−(x)2ddxsin−1x=11−(x)2
Derivative of inverse cosine function ddxcos−1x=−11−(x)2ddxcos−1x=−11−(x)2
Derivative of inverse tangent function ddxtan−1x=11+(x)2ddxtan−1x=11+(x)2
Derivative of inverse cotangent function ddxcot−1x=−11+(x)2ddxcot−1x=−11+(x)2
Derivative of inverse secant function ddxsec−1x=1|x|(x)2−1ddxsec−1x=1|x|(x)2−1
Derivative of inverse cosecant function ddxcsc−1x=−1|x|(x)2−1ddxcsc−1x=−1|x|(x)2−1
Derivative of the natural exponential function ddx(eg(x))=eg(x)g′(x)ddx(eg(x))=eg(x)g′(x)
Derivative of the natural logarithmic function ddx(lng(x))=1g(x)g′(x)ddx(lng(x))=1g(x)g′(x)
Derivative of the general exponential function ddx(bg(x))=bg(x)g′(x)lnbddx(bg(x))=bg(x)g′(x)lnb
Derivative of the general logarithmic function ddx(logbg(x))=g′(x)g(x)lnbddx(logbg(x))=g′(x)g(x)lnb