SOLUTION: I need help verifying the following identity: (sin B + cos B) (sin B - cos B) = 2 sin^2 B - 1

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Question 476393: I need help verifying the following identity:
(sin B + cos B) (sin B - cos B) = 2 sin^2 B - 1
Answer by Tatiana_Stebko(1539) About Me  (Show Source):
You can put this solution on YOUR website!
%28sin+B+%2B+cos+B%29+%28sin+B+-+cos+B%29+=+2+%28sin%28+B%29%29%5E2-+1
Use formula %28a%2Bb%29%28a-b%29=a%5E2-b%5E2
%28sin+B+%2B+cos+B%29+%28sin+B+-+cos+B%29+=%28sinB%29%5E2-%28cosB%29%5E2
Use formula %28sinB%29%5E2%2B%28cosB%29%5E2=1 => %28cosB%29%5E2=1-%28sinB%29%5E2