Question

cos^2A+3sinA=3 solve it ​

Answer 1

Answer:     3sin(A)=1+cos(2A)

or,−cos(2A)+3sin(A)−1=0

using the identity,cos(2x)=1−2sin2(x)

−(1−2sin2(A))−1+3sin(A)=0

−2+2sin2(A)+3sin(A)=0

Let sin(A)=u

−2+2u2+3u=0

solving it,we get, u=12,:u=−2

substituting back,sin(A)=u

sin(A)=12andsin(A)=−2

So,sin(A)=−2i.e none

and,sin(A)=12 C

Finally,combining all the solutions,

 :  A=π6+2πn,:A=5π6+2πn#