I really don't like trig functions so could someone give this the once over?

"Find f'''(x) of f(x) 6x^5 + 3xcosx"

f'(x) = 30 x^4 + 3x(-sinx) + 3cosx

f''(x) = 120x^3 + -3x(cosx) + -sinx

f'''(x) = 360x^2 + 3x(sinx) + -cosx

Did I do this right???

Thanks in advance