Question

f(x) = 3sin(x)-2cos(x)

Answer 1

\[=√(2^2+3^2)cos(x- \phi); \phi=arctan(2/3) \]
\[=√13cos(x-arctan(2/3)\]

Answer 2

is this the correct simplified form?

Answer 3

no, there's a negative sign outside

Answer 4

where did i miss the sign?

Answer 5

f(x) = -(2 cos x - 3 sin x)
so
f(x) = - sqrt(13) cos(x - phi)
where phi = arctan(-3/2)

Answer 6

so the arctangent stays in the solution .?

Answer 7

sure

Answer 8

cool thanks

Answer 9

just be sure of course you're using arctan the function with range (-pi/2,pi/2), vs. arctan the relation.

Answer 10

i am not sure ,