trig identites/ proofs (1 Viewer)

[NizDiz]

Hi guys, may some help me with basic trig proofs- forgot!!!! with result of sin^2 x + cos^2 x = 1, how to find sin x and cos x?

All help appreciated Thanks guys

 

[asianese]

You'll need more information before you 'find' sinx...

 

[Locus]

Alright, from what I've read, you're trying to prove sin^2 x + cos^2 x = 1

You first have to draw a right-angle triangle. A hypotenuse of 1 is preferable but it doesn't really matter. You can label the height Y and the base X and one of the angles (not the 90 degrees) as theta. Then sin.theta and cos.theta will be X or Y depending on which angle you chose as theta. Then you Pythagoras Theorem which gives you the relationship X^2 + Y^2 = 1. Then sub in the X and Y which you found in terms of sin.theta and cos.theta.