 Hello and welcome to the session. In this session we are going to discuss the following question and the question says that write 15 into cos of minus 56.3 degrees plus j sin of minus 56.3 degrees the whole in j operator form. We know that a plus jb is equal to r into cos theta plus j sin theta in polar form where a is equal to r cos theta and b is equal to r sin theta. With this key idea let us proceed with the solution. According to the question we have to convert 15 cos minus 56.3 degrees plus j sin minus 56.3 degrees the whole in j operator form that is we have to convert it in a plus jb form. We know a plus jb is equal to r into cos theta plus j sin theta in polar form so on comparing 15 into cos of minus 56.3 degrees plus j sin minus 56.3 degrees the whole with r into cos theta plus j sin theta the whole we get r is equal to 15 and theta is equal to minus 56.3 degrees. Now since a is equal to r cos theta and b is equal to r sin theta therefore on putting the values of r and theta we get a is equal to 15 cos minus 56.3 degrees and b is equal to 15 sin minus 56.3 degrees as cos of minus theta is equal to cos theta this implies a is equal to 15 cos 56.3 degrees this implies a is approximately equal to 8.32 this value can be calculated by using a calculator as sin of minus theta is equal to minus sin theta this implies b is equal to minus 15 sin of 56.3 degrees this implies that b is approximately equal to minus 12.5 which can be calculated using a calculator so a plus jb is equal to 8.32 minus j into 12.5 this is the required form with this we complete our session hope you enjoyed the session