The equation cos (α - β) × cos (α + β) ≠ cos² α - cos² β. Then the given equation is incorrect.
What is trigonometry?
Trigonometry deals with the relationship between the sides and angles of a right-angle triangle.
The equation is given below.
cos (α - β) × cos (α + β) = cos² α - cos² β
Then show whether the equation is correct or incorrect.
Taking the left-hand side, then we have
[tex]\cos(\alpha-\beta)*\cos(\alpha +\beta) = (\cos \alpha \cos\beta + \sin \alpha \sin \beta ) (\cos \alpha \cos\beta - \sin\alpha \sin\beta )\\\\\cos(\alpha-\beta)*\cos(\alpha +\beta) = \cos ^2 \alpha \cos ^2\beta - \sin ^2 \alpha \sin ^2\beta[/tex]
The left-hand side does not equal to the right-hand side.
More about the trigonometry link is given below.
https://brainly.com/question/22698523
#SPJ4