- #1

rxh140630

- 60

- 11

- Homework Statement
- Prove that if A, B are given real numbers there exists C and ∝ with C ≥ 0 such that Ccos(x+∝) = Asinx + Bcosx. Determine C and ∝ if A=B=1

- Relevant Equations
- cos(x+y)= cosxcosy-sinxsiny

Author gave solution [itex]C = \sqrt{2}, ∝ = -pi/4[/itex]

but plugging [itex]C = - \sqrt{2}, ∝ = -3pi/4[/itex] into cos(x+y) and leaving the x I get [itex]\sqrt{2}Cos(x+3pi/4) = sinx+cosx[/itex]

Is my answer valid as well?

but plugging [itex]C = - \sqrt{2}, ∝ = -3pi/4[/itex] into cos(x+y) and leaving the x I get [itex]\sqrt{2}Cos(x+3pi/4) = sinx+cosx[/itex]

Is my answer valid as well?