Question

if sinx=3/5 where 0<x<π/4 then find cos2x​

Answer 1

$heya \\ \\ \\ \cos(2x) = 1 - 2 \sin {}^{2} (x ) \\ \\ \\ \\ \sin(x) = 3 \div 5 \\ \\ \\ \sin {}^{2} (x) = 9 \div 25 \\ \\ \\ \\ so \: \: cos(2x) = 1 - 9 \div 25 \\ \\ \\ \\ \cos(2x) = 16 \div 25$

Answer 2

i attached ans above....

we know that cos 2x=1-2sin^2(X)

given

sinx=3/5

on putting the value

cos 2x=1-2*9/25

cos 2x=7/25

since cos lie in 1 St quadrent so it is positive

cos x=7/25