Can someone point out where I am going wrong?

The vector in the drawing has a magnitude of 750 units.

(a) Determine the magnitude of thexandycomponents of the vector , relative to the black axes.

Ax= 650 units

Ay= 375 units

(b) Determine the magnitude and direction of thexandycomponents of the vector , relative to the colored axes.

Ax'= 575 units

Ay'= 482 units

My question is why is Ay' not just 750cos50?

Thanks.