Derivative Rules Summary Constant Rule The derivative of any constant is zero. If f(x)=c, then f'(x)=0. f(x)=15 f'(x)=0 g(x)=−π g'(x)=0 h(x)=e^2 h'(x)=0 y=7 y'=0 s(t)=1/2 s'(t)=0 f(x)=sin(6π) f'(x)=0 Constant Multiple Rule The derivative of a constant times a function is the constant times the derivative of the function. If f(x)=c⋅g(x), then f'(x)=c⋅g'(x). f(x)=5x^3 f'(x)=15x^2 g(x)=(1/2)sin(x) g'(x)=(1/2)cos(x) h(x)=−4e^x h'(x)=−4e^x y=8ln(x) y'=8/x f(x)=(3/2)x^(1/2) f'(x)=(3/2)(1/2)x^(−1/2)=3/(2√x) y=10x^(−2) y'=−20/x^3 Sum Rule The derivative of a sum of functions is the sum of their derivatives. If f(x)=g(x)+h(x), then f'(x)=g'(x)+h'(x). f(x)=x^2 + 4x f'(x)=2x+4 g(x)=sin(x)+e^x g'(x)=cos(x)+e^x h(x)=7x^5 + ln(x) h'(x)=35x^4 + 1/x y=x^4 + x^(−1) + 3 f(x)=5√x + 1/x f(t)=t^3 + cos(t)−9 y'=4x^3 − 1/x^2 f'(x)=5/(2√x) − 1/x^2 f'(t)=3t^2 − sin(t) Difference Rule The derivative of a difference of functions is the difference of their derivatives. If f(x)=g(x)−h(x), then f'(x)=g'(x)−h'(x). f(x)=3x^4 − 2x^2 f'(x)=12x^3 − 4x g(x)=cos(x)−e^x g'(x)=−sin(x)−e^x h(x)=ln(x)−5x h'(x)=1/x − 5 Derivative Rules Summary y=12x−sin(x) y'=12−cos(x) f(t)=t^(−3) − 4t^2 f'(t)=−3t^(−4) − 8t y=x^(1/3) − x^(2/3) y'=1/(3x^(2/3)) − 2/(3x^(1/3)) Product Rule If f(x)=g(x)⋅h(x), then f'(x)=g'(x)h(x)+h'(x)g(x). f(x)=x^2 sin(x) f'(x)=x^2 cos(x)+2xsin(x) g(x)=e^x cos(x) g'(x)=e^x cos(x)−e^x sin(x) h(x)=(x^3 − 2x)(ln(x)) y=(x+1)(x^2 +3x−2) f(t)=√t e^t f(x)=3x^2 tan(x) h'(x)=(x^3 − 2x)(1/x)+(ln(x))(3x^2 − 2) y'=3x^2 + 8x + 1 f'(t)=√t e^t + (1/(2√t)) e^t f'(x)=3x^2 sec^2(x) + 6x tan(x) Quotient Rule If f(x)=h(x)/g(x), then f'(x)= [g(x)h'(x)−h(x)g'(x)] / [g(x)]^2 f(x)=(x−1)/(x+1) f'(x)=−2/(x+1)^2 g(x)=cos(x)/sin(x) g'(x)=sec^2(x) h(x)=e^x/x^2 h'(x)=e^x(2x−x^2)/x^4 y=x/ln(x) f(x)=(x^3+1)/e^x y=(x^2+1)/1 y'= [1−ln(x)] / [ln(x)]^2 f'(x)=e^x(x^3−3x^2+1)/e^(2x) y'=0 Chain Rule The derivative of a composite function f(g(x)) is f'(g(x))⋅g'(x). f(x)=(x^2 +1)^3 f'(x)=6x(x^2 +1)^2 g(x)=sin(4x) g'(x)=4cos(4x) h(x)=e^(5x) h'(x)=5e^(5x) y=ln(x^3 + x) y'=(3x^2 + 1)/(x^3 + x) f(x)=√(x^2 −3) f'(x)=x/√(x^2 −3) y=cos^2(x) y'=−2sin(x)cos(x)