Question 975223


Most Pre-calculus(Alg/Trig) and Calculus textbooks will have the unit circle with quadrants, angles and terminal points either in the back or front of the book for reference. 


If not, convert radians to degrees by multiplying {{{((7pi)/4)*(180/pi) = 315 deg}}} which is in Quadrant IV of the unit circle.


To find the reference angle: 360 - 315  = 45 degrees is equivalent to {{{pi/4}}} with (cos,sine) values of {{{cos(pi/4) = sqrt(2)/2}}},  {{{sine(pi/4) = sqrt(2)/2}}}.


Since we are in Quadrant IV sine will be negative {{{cos(7pi/4) = sqrt(2)/2}}} and {{{sine(7pi/4) = -sqrt(2)/2}}}.


The terminal point is P(x,y) = {{{sqrt(2)/2}}}, {{{-sqrt(2)/2}}}.




Best,

Farohw