Question

If cos a + sin a = root 2 cos a prove that cos a - sin a = root 2 sina

Answer 1

Answer: cos a = root 2 cos a - cos a

or sina = cosa( root 2 - 1)

or sina/(root 2 - 1)= cos a

or sina( root 2 + 1 ) = cos a

or root 2 sin a + sin a = cos a

or root 2 sin a = cos a - sin a

Step-by-step explanation: