Signals and Systems - Electrical Engineering

APPENDIX Useful Formulas.......................................................................................

Trigonometric Relations

Reciprocal

csc(θ)=

1

sin(θ)

sec(θ)=

1

cos(θ)

cot(θ)=

1

tan(θ)

Pythagorean Identity

sin^2 (θ)+cos^2 (θ)= 1

Sum and Difference of Angles

sin(θ±φ)=sin(θ)cos(φ)±cos(θ)sin(φ)

sin( 2 θ)=2 sin(θ)cos(θ)

cos(θ±φ)=cos(θ)cos(φ)∓sin(θ)sin(φ)

cos( 2 θ)=cos^2 (θ)−sin^2 (θ)

Multiple Angle

sin(nθ)=2 sin((n− 1 )θ)cos(θ)−sin((n− 2 )θ)

cos(nθ)=2 cos((n− 1 )θ)cos(θ)−cos((n− 2 )θ)

Signals and Systems Using MATLAB®. DOI: 10.1016/B978-0-12-374716-7.00017-x

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