## 4 thoughts on “2.12”

1. serge-tkzdyahoo-com says:

Why is Beta = 178.201 degrees, not -1.799 degrees?

1. tutorpaul says:

Because your calculator is a liar. Note that the angle we are describing terminates in quadrant 2 not quadrant 4. The arctan function can only return values between $-90^\circ$ and $90^\circ$, so we must always interpret the results from the arctan function to ensure that they are sane with regard to the terminal quadrant that the angle we are describing.

2. bbbrranndddoon says:

for ar and atheta i got 10^3 not 10^4

1. tutorpaul says:

Looks like you're right! Checking my work shows $10^3$ should be the order of magnitude.