Question

Root under2+root under2+2cos4theta​

Answer 1

$hello$

=> 2+2cos4θ=4(cos

2

2θ)

=> 2cos4θ=4(cos

2

2θ)−2

=> 2cos4θ=2(2cos

2

2θ−1)

=> 2cos4θ=2(cos4θ)

=> LHS=RHS

Hence proved

Answer 2

Answer:

good evening

have a nice day