Question

1) I plugged in 30cos20 but I got 28.19
2) how did you get from 28.01 to 0.34

Answer 1

1) 30cos20 should indeed give approximately 28.19, assuming the angle is in degrees.

2) Without context, it's hard to explain how 28.01 could become 0.34. Could you provide more details about the problem or calculation?