Question

cos43°≈a,cos47° kaa maan nikaale

Answer 1

$\sqrt{3 - 4}$

Answer 2

since ,cos 43°=cos(90°-47°)=sin47°

since sin^2(47°)+cos^2(47°)=1
hence
cos(47°)=√1-sin^2(47°)
cis47°=√1-a^2