Trig

[Zuheila]

I know that I can use substitution to solve that equation. (cos^2x = 1/2 + sin^2x). From here I'll either want to replace sin^2x or cos^2x using the Pythagorean Identity, this will allow the equation to be based on only one function, and not two (sin and cos) right?

 

[Deleted member 4993]

View attachment 27562

I know that I can use substitution to solve that equation. (cos^2x = 1/2 + sin^2x). From here I'll either want to replace sin^2x or cos^2x using the Pythagorean Identity, this will allow the equation to be based on only one function, and not two (sin and cos) right?

Use the fact:

cos²(x) + sin²(x) = 1

Please show us what you have tried and exactly where you are stuck.

Please follow the rules of posting in this forum, as enunciated at:

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Please share your work/thoughts about this problem

 

[Steven G]

You are correct. Please proceed and show us your work!

 

[lex]

Or subtract the 2 equations and use [MATH] \hspace2ex \cos^2x-\sin^2x=\cos{2x}[/MATH]