find the next two positive and negative angles coterminal with the quadrantal angle.

90 degrees.

would the answer be.....
would it be 450, 810??????
and -630, -270 ????

Yes, see my reply to your previous question

http://www.jiskha.com/display.cgi?id=1314596365

To find the next two positive and negative angles coterminal with 90 degrees, we need to add or subtract multiples of 360 degrees from the given angle.

Starting with the positive angles, we add multiples of 360 to 90 degrees:
90 + 360 = 450 degrees
90 + 2(360) = 810 degrees

Next, for the negative angles, we subtract multiples of 360 from 90 degrees:
90 - 360 = -270 degrees
90 - 2(360) = -630 degrees

Therefore, the next two positive angles coterminal with 90 degrees are 450 degrees and 810 degrees. And the next two negative angles coterminal with 90 degrees are -270 degrees and -630 degrees.