A-Level Maths: E6-10 Equivalent Forms: Writing 4cosθ + 3sinθ in the form rsin(θ+ɑ)

[drdankmeme]

Just putting it out there for you guys. Anyone who got 53 instead of 0.92 needs to make sure their calculator is set to radians and not degrees for these questions

[kakashi]

I don't understand why u did the eqation2/equation 1 thing when u can just visually see from the triangle that tan alpha = 4/3

[wilhelmvongreim]

Hello sir,
I did this and wrote the answer as 5sin[θ+arctan(4/3)]. Would I have to transform the arctan bit into radians, or would this also be okay?
Thank you.