I have some wrong answers .. help?

Calculate the area between y-sin(x) and y=cos(x) , -pi<or equal to x <or equal to 2pi.

I have -1.9984.

Calculate the area between y=x^2 and y=3x+4.

I have -18.7.

Find the area of the region enclosed between y=2sin(x) and y=2cos(x) from x=0 and x=0.8pi

I have .6334465.

Can someone tell me what i did wrong?