Question

cos(3π÷4+x) - cos(3π÷4-x) =-√2 sinx​

Answer 1

Answer:

cos(

4

3π

+x)−cos(

4

3π

−x)

=cos

4

3π

cosx−sin

4

3π

sinx−cos

4

3π

cosx−sin

4

3π

sinx

=−2sin

4

3π

sinx

=−2(−sin

4

π

)sinx

=

2

sinx