Evaluate without using a calculator or tables

sin(pi/3 - 3pi/4)

The answer is - 1+ square root of 3 / 2 square root of 2

How do I get this answer?

1 answer

If it makes it any easier for you to see the angles in degrees, convert them

pi/3 radians = 60ยบ and 3pi/4 = 135

so sin(pi/3-3pi/4) = sin(60-135) = sin
(-75)

now sin(-75) = -sin(75)
-sin(75) = -sin(45+30)

use the formula we used in the previous posted like questions.
I will check your answer.