Question

if cosx=u/sq(u^2+1), find expression for sin2x in terms of u

Answer 1

\[\cos x=\frac{ u }{ \sqrt{u^2+1} }\]

Answer 2

Sin2x = 2 sinx cosx

sin^2 x + cos^2 x =1

Answer 3

u have cos x find sinx first.....using sin^2 x + cos^2 x =1

and subs the value in Sin2x = 2 sinx cosx

Answer 4

can you please explain further