
equation using identites
solve the following equation for A, giving all the roots in the interval 0<A<360 (including 0 and 360, i don't know how to write the dash under the sign) correct to the nearest dp:
4((sinA)^2)cosA=(tanA)^2
ok i already know my results are wrong, i don't want the answers i just want to know where i went wrong
so using tan=sinA/cosA, i eliminate (sinA)^2 from both sides of the equation
which gives 4cosA=1/(cosA^2)
=> (cosA^3)=1/4
=> cosA=1/sqrt2
A= 45, 315
where am i wrong?


Or take roots from here...
The same form is:
Cos[x/2]^2*Csc[[Pi]/4  x/2]^2 Csc[[Pi]/4 + x/2]^2*Sin[x/2]^2 (1 + Cos[3 x]+3*Cos[x]) =0
Best Regards!