Sin^2x + sin^2x + cos²x

A. 2 sinx cosx - 1 + 2 sin^2 x.

Step-by-step explanation:

sin2x = 2 sinx cosx

cos2x = cos^2x - sin^2x

So sin2x - cos2x =  2 sinx cosx - ( cos^2x - sin^2x)

But cos^2 x = 1 - sin^2 x, so we have:

2 sinx cosx - (1 - sin^2 x - sin^2x)

= 2 sinx cosx - 1 + 2 sin^2 x.

9.55 degrees.

step-by-step explanation:

the given angle is

1 cycle is equal to 2π radians. so 4π will be equal to two cycles.

5.166667π-4π = 1.166667π

hence, this angle goes a little more than negative x axis.

1.166667π-π= 0.166667π

hence, the reference angle is 0.166667π radians.

1 radian = 57.2958 degrees

now, in degrees, this should be equals to 9.55 degrees.