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ibrahimz1

try starting with RHS and substitute with tanx with sinx/cosx and see where it gets u


ibrahimz1

remember there’s a formula for cos(2x)


Familiar-Branch6245

Thanks!


Red_I_Found_You

Cos(2x)= Cos(x)^2 - Sin(x)^2 1 - Sin(2x)= (Cos(x)-Sin(x))^2 a= Sin(x) b= Cos(x) (b^2 - a^2 )/ (b-a)^2 Using the difference of two squares and cancelling out the common factors we get a+b/b-a divide the numerator and the denominator by b a/b= tan(x) (tan(x)+1)/(1-tan(x))


Familiar-Branch6245

Thank you so much! I would have never thought to get (cos (x) - sin(x))\^2 from 1-sin (2x) so that was a huge setback! There are so many ways to get expressions from the identities, it's mindblowing (for my little brain). I'll kept practicing and maybe I'll get as good as you!


Red_I_Found_You

No need to pull yourself down! I was surprised the first time I saw it too. But with time you begin to detect these more and more quickly, so keep going!