I am looking for a positive and negative coterminal angle to

I am looking for a positive and negative co-terminal angle to theta when given theta = 19^c/7. The answer is supposed to be in radians. Thanks!

Solution

A positive coterminal angle to angle A may be obtained by adding 360^o(2pi), 2*(360)^o (4pi), 2*n*pi, where n is +ve integer

So, A positive coterminal angle A_c=19^c/7+2n*pi

A negative coterminal angle to angle A may be obtained by adding -360^o(2pi), -2(360)^o(4pi), -2*n*pi where n is -ve integer (or any other negative angle multiple of 360^o).

So, A negative coterminal angle A_c =19^c/7-2n*pi