[SOLVED] Radians/degrees conversions, want confirmation of answers

k well ... i did the following

1. Convert the angle given in degrees to radian measure in terms of pi.

380*

Round the coefficient to two decimal places

well i converted 380* in terms of pi

and i got : 19/9 pi ( its wrong)

2. Evaluate to four significant digits.

sin^2 pi/3 + cos pi/3

sin^2 pi/3 + cos pi/3

and i got : 1.019 ( and this is wrong as well)

3. A satellite is in a circular orbit 225 km above the equator of the earth. How many kilometres must it travel for its longitude to change by 86.3°? Assume the radius of the earth equals 6400 kilometres.

Round the answer to the whole.

86.3* x pi/180* = 1.506 rad theta = s / r

1.506 rad x 225 km = s

338.89 = s ( rounded to the nearest whole number)

340 = s ?

4. Solve the equation 8- tan theta = 0 for all nonnegative values of theta less than 360* . Do by calculator, if needed, and give the answers to three significant digits in the order of increasing.

inverse tan (8) = angle

theta = 82.9 (3 sig figs)

theta = 263 (3 sig figs)