Froving trigonometric identities Problem type 2 Prove the id

Froving trigonometric identities: Problem type 2 Prove the identity. (cot 2x 1)(sin x-1) cotx Note that each Statement must be based on a Rule chosen from the Rule menu. To see a deta mark. Rule Statement cotx 1)(sin r 1) Rul Click here to validate this line; click on Check below to submit your answer.

Solution

(cot²x +1)(sin²x -1)

=((cosx/sinx)² +1)(sin²x -1) .......................................cotx =cosx/sinx

=((cos²x+sin²x)/sin²x)(sin²x -1)

=((1)/sin²x)(-cos²x)..................................................cos²x+sin²x=1 is identity=>sin²x-1=-cos²x

=-cos²x/sin²x

=-(cotx/sinx)²

=-cot²x......................................................................cosx/sinx=cotx