Question

give me answer please my dear siso or bro... prove it​

Answer 1

Answer:

zxfaf2r443grvedrrt3rgg gft

Answer 2

Answer:

cos20°.cos40°.cos60°.cos80°

=1/2(2cos40°cos20°)1/2.cos80

               2CosAcosB=(cos(A+B)+cos(A-B)

=1/4{(cos(40+20)+cos(40-20))}cos80

=1/4{cos60+cos20}cos80

=1/4{cos80.cos60+cos80.cos20}

=1/4{1/2.cos80+1/2(cos(80+20)+cos(80-20)}

=1/8{cos80+cos100+cos60}

=1/8{cos80+cos(180-100)+cos60}

=1/8{cos80-cos80+cos60}

=1/8x1/2

=1/16

hope this helps you

mark me as the brainliest