what is the reference of angle im lost

Question

Without using a calculator, compute the sine and cosine of $315^{\circ}$ by using the reference angle.What is the reference angle? ____ degrees.

In what quadrant is this angle? ____ (answer 1, 2, 3, or 4)

$\sin (315^{\circ}) =$ $\cos (315^{\circ}) =$ (Type sqrt(2) for $\sqrt{2}$ and sqrt(3) for $\sqrt{3}$ .)

Raymond B. · Accepted Answer

sin315 = sin(360-315) = sin(-45) = -1/sqr2 cos315 = cos(360-315) = cos(-45) = 1/sqr2

1 Expert Answer