express in terms of the reference angle?

Enriqueta Steffen: I dont know why they have five decimal places, but i will take the quadrant boundaries to 6, so the answer can be rounded to 5The reference angle is in quadrant I, between 0 and pi/2 radians. (pi/2= 1.570796 approx.)But you need to know the other quadrants too.Q2 (1.570796,3.141593). Q3 (3.141593,4.712389). Q4(4.712389,6.283185)Using a for the given angle1) 4.28654 is in Q3 the sine will be negative . The reference angle is (a-pi), 4.28654-pi, so your expRession is -sin (1.14495)2)cos 1.83572 This is in Q2. The cosine is negative. The reference angle is pi-(a), 1.30587So -cos(1.30587).3)tan 5.80729. This is in Q4. The tangent is negative. The reference angle is 2pi-a, 0.47590So -tan0.47590***if you get stuck, remember what you do with degrees to find reference angles:Q2(180-a)->(pi-a)Q3:(a-180)->(a-pi)Q4:(360-a)->(2pi-a)Hoping this helps!...Show more