Show that sin^4 theta - cos^4 theta = 1 - 2 cos^theta
Answers
Answered by
4
hello there!!!
i will be using A instead of theta
sin⁴A-cos⁴A=(sin²A)²-(cos²A)²
=>(sin²A+cos²A)(sin²A-cos²A)
=>(1)(sin²A-cos²A)
=> (1-cos²A-cos²A). [ since sin²A = 1-cos²A]
=>1-2cos²A
hope this helped you
i will be using A instead of theta
sin⁴A-cos⁴A=(sin²A)²-(cos²A)²
=>(sin²A+cos²A)(sin²A-cos²A)
=>(1)(sin²A-cos²A)
=> (1-cos²A-cos²A). [ since sin²A = 1-cos²A]
=>1-2cos²A
hope this helped you
Similar questions