The graph of y = cos (x - 1.3) is a sinusoid with a phase displacement of 1.3 radians.

Given that cos 1.3 ≈ 0.27 and sin 1.3 ≈ 0.96, write y as a linear combination of cos x and sin x.

My responce:

$\displaystyle y=cosxcos1.3+sinxsin1.3$

I'm new to linear equations so I want to make sure I'm doing this correctly...