Answer:
see explanation
Step-by-step explanation:
Using the sum/ difference → product formula
cos x - cos y = - 2sin( 
)sin (
)
sin x - sin y = 2cos ( )sin ( )
Given
(cosA - cosB)² + (sinA - sinB )²
= [ - 2sin(
)sin(
) ]² + [ 2cos( )sin( ) ]²
= 4sin² ( )sin² ( ) + 4cos² ( )sin² ( )
= 4sin² ( )[ sin² ( ) + cos² ( ) ← sin²x + cos²x = 1
= 4sin² ( ) × 1
= 4sin² ( ) = right side ⇒ proven
4 (i literally had to think about this cause i thought it was too easy )
Enter them into a calculator (most significant digit first), pressing the "+" key between them and the "=" key after the last one.
