Question

(cos^4 A - sin ^4 A) =

Answer 1

Answer:

(cos^2A)^2-(sin^2A)^2A=(cos^2A+sin^A)(cos^2A-sin^2A)

1×{cos^2A-(1-cos^2A)}

cos^2A-1+cos^2A=2cos ^2A-1.

OR

Step-by-step explanation:

you can solve it by this or in place of cos square A minus sin square you can put the value minus 11 into one will give you answer -1