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Calculus/trigonometry

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Expert: Alon Mandes - 9/2/2009


Question
using the definitions of sine and cosine, prove that sin^2t + cos^2t = 1

Answer

The drawing
One of the quickest way to prove it is by taking a right triangle with hypotenuse equals 1 .
See image attached.
In this case , we may claim that :
sinx=a/1 --> a=sinx
cosx=b/1 --> b=cosx
Now we apply Pythagoras rule:
a^2+b^2=c^2 . In our case we took c=1 , & therefore :
sin^2x+cos^2x=1 .

Alon.

Alon Mandes

Expertise

Kind of questions I can answer : Limits, Derivatives, Integration, Implicit functions, continuousity, differentiation ,Extremum problems, Lagrange multipliers, Gradients, Surface integrals, Multi variables functions ,Multi variables Integrals,Complex variables ,Complex functions, Curves, Trajectory integrals & Vector analyse,Divergence,Rotor & word problems. Kind of question I can't answer : Economics,Combinatorics,infinite series & convergence ,Statistics & Probabilities .

Experience

1. I'm a team member of mathnerds (math site for answering questions) 2. I'm a team member in the Student's Union of the Technion, helping students who have problems in mathematics. 3. 2 years of experience as a math teacher in college. 4. I give free homework help for high school students in Mathematics & Physics. 5. I teach part time in collage the subjects : "Digital Signal Processing" , "Random Signals & Noise" , "Complex Functions".

Organizations
Hi-Tech company : GSM4VOIP ; job possition : Algorythm developer.

Education/Credentials
M.A in Mathematics & Bs.c in Electronics.

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