I need to convert (7.4,2.5) from polar to rectangular coordinates. I know that: x = r cos u y = r sin u So...? x = (7.4)cos(2.5) y = (7.4)sin(2.5) The answer is (-5.9,4.4) but I don't know why! How do you find the sin/cos of 2.5?
and those are your answers....without a calculator you will find it difficult to evaluate the sine and cosine.. those calculators exist online...