Trig equation

[Albi]

cos(3x-π/4)=sin(x)
Can someone help me solve this equation?

 

[pka]

cos(3x-π/4)=sin(x)
Can someone help me solve this equation?

There are quite a few solutions: SEE HERE

 

[Deleted member 4993]

cos(3x-π/4)=sin(x)
Can someone help me solve this equation?

Use the identity:

\(\displaystyle sin[x] = cos[(4n+1)\frac{\pi}{2} \ - \ x]\)

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:

https://www.freemathhelp.com/forum/threads/read-before-posting.109846/#post-486520​

Please share your work/thoughts about this problem.

 

[Dr.Peterson]

cos(3x-π/4)=sin(x)
Can someone help me solve this equation?

I would probably start with the cofunction identity, replacing sin(x) with cos(pi/2 - x). Then you have two equal cosines, and can consider the two conditions under which the cosines of angles can be equal: either they are coterminal, or one is coterminal with the negative of the other.